As president, Donald Trump imposed an array of deeply divisive immigration restrictions on both Latinos and Muslims. And yet from 2016 to 2020, he increased his share of the vote among both groups. Even some Latino and Muslim voters who opposed Trump’s immigration agenda moved to support him anyway because of his record on other issues, particularly the economy and conservative social priorities.

Now Trump and several of his rivals for the 2024 GOP presidential nomination are doubling down on the bet that they can target each group with harsh immigration policies without paying an electoral price.

For months, they have proposed an escalating succession of hard-line measures aimed at deterring mostly Latino undocumented migrants from crossing the southern border. And following the Hamas terror attack on Israel earlier this month, they rolled out a wave of exclusionary proposals aimed at Muslims. Trump has pledged that, if returned to the White House, he will restore his travel ban on people from a number of majority-Muslim nations, expand ideological screening of all potential immigrants to ensure that they agree with “our religion,” and deport foreign students in the United States who express hostility to Israel.

Trump and other GOP 2024 candidates such as Florida Governor Ron DeSantis have unveiled these proposals even as many Democratic-leaning activists warn that support for President Joe Biden is suffering in Latino and Muslim communities. Polls have consistently shown widespread discontent among Latinos over inflation and the economy. And many Muslim Americans are angry at Biden for his strong support of Israeli Prime Minister Benjamin Netanyahu, as he pursues his military campaign to destroy Hamas in Gaza. “There is a level of disgust and disbelief and disappointment at the administration’s handling of the crisis so far,” Edward Ahmed Mitchell, the national deputy director of the Council on American-Islamic Relations, told me.

The movement of some of these voters away from Biden produces a powerful incentive for Republicans to escalate their rhetorical and policy offensive against immigrant communities. It means that Trump could achieve the best of both worlds politically: offering a harsh anti-immigrant agenda that energizes the most xenophobic white voters in his coalition while still maintaining, or even growing, his support among immigrant communities drawn to him (or repelled by Democrats) on other issues.

That process already seems well under way in the agenda that Trump and other Republicans are advancing about the southern border. The fact that Trump’s vote among Hispanics improved in 2020, even after he implemented such aggressive policies as starting the border wall and separating migrant children from their parents, has undoubtedly encouraged him to go even further with his new proposals for mass deportation of undocumented migrants in the U.S. and military action against Mexico (both of which DeSantis has also endorsed).

Likewise, if Trump wins the 2024 election and more Muslim Americans vote for him than in 2020, despite his threats to target Muslim immigrants, he will undoubtedly feel emboldened in a second term to impose more exclusionary policies on that community. Stephen Miller, the hard-line architect of much of Trump’s immigration agenda as president, offered a preview of the deportation agenda that might be ahead when he posted a video of a recent pro-Palestinian demonstration and wrote that ICE agents “will be busy in 2025.”

Over his four years in office, Trump instituted policies more resistant to immigration than any president had since the 1920s, and repeatedly disparaged immigrants with openly racist language (including calling Mexicans “rapists” and decrying immigration from mostly Black “shithole countries”). He is now pushing beyond even that agenda. “What comes next will be … spectacular,” Miller posted recently.

As just a first step, Trump has proposed to reinstate all of the key policies he implemented that raised nearly insurmountable hurdles for those who sought to claim asylum in the U.S., including the “remain in Mexico” policy that required asylum seekers to stay in that country, typically in crowded and dangerous makeshift camps, while their cases were adjudicated. He’s promised to finish his border wall. And during his CNN town hall last spring, Trump refused to rule out reinstating the separation of migrant children from their parents, his most controversial policy. The Biden administration has reversed all of these policies, and it recently settled a lawsuit in which the federal government agreed not to restore the child-separation policy. Still, experts say that a reelected Trump would almost certainly seek to void or evade that agreement.

After the Hamas attack in Israel, Trump also pledged to bring back his travel ban. A bitterly divided Supreme Court upheld the rule in a 5–4 vote in 2018; if reelected, Trump could unilaterally restore the policy through executive action. “The legal framework,” Mitchell from the Council on American-Islamic Relations told me, “is still there just waiting to be used.”

But Trump has new ideas too. These include ending birthright citizenship (though his legal authority to do so is highly questionable) and launching military actions against Mexican drug cartels. In a speech to a conservative group earlier this year, he promised to “use all necessary state, local, federal, and military resources to carry out the largest domestic deportation operation in American history.”

He is also calling for requiring prospective immigrants from any country to pass intensified ideological screenings: “If you want to abolish the state of Israel, you’re disqualified; if you support Hamas or the ideology behind Hamas, you’re disqualified; and if you’re a communist, Marxist, or fascist, you are disqualified,” he said earlier this month in Iowa. Monday in New Hampshire, Trump raised the ante when he said he would bar entry for those who “don’t like our religion,” without explaining how he defined “our religion.” He’s pledged to deport students and other immigrants who express what he called “jihadist sympathies.”

David Leopold, a former president of the American Immigration Lawyers Association, says Trump’s record as president shows that it would be a mistake to dismiss even the most extreme of these proposals as simply campaign rhetoric designed to stir his crowds. “Every word that comes out of Donald Trump’s mouth ought to be taken seriously,” Leopold told me. If Trump returns to power, he said, we will see a version of his first term’s “anti-immigrant policy on steroids.”

While Trump was president, and his agenda was in the spotlight, most of his core immigration policies provoked majority opposition in polls. In a compilation of results from its annual American Values Survey polls late in Trump’s presidency, the nonpartisan Public Religion Research Institute (PRRI) found that just over half of Americans opposed his Muslim travel ban, about three-fifths opposed his border wall, and fully three-fourths opposed the child-separation policy.

But public tolerance for some of these ideas may be growing amid dissatisfaction with Biden’s record in managing the border and immigration. Less than a third of adults overall—and only about one-fourth of independents—said they approved of Biden’s handling of those issues in the latest annual American Values Survey, released yesterday. A recent national Marquette University Law School Poll found that Americans preferred Trump over Biden on controlling the border by nearly two to one.

A recent Quinnipiac University national poll found that a majority of Americans support building a border wall for the first time since the pollsters initially asked about the idea, in 2016. “With frustration building” over Biden’s record on immigration, “it looks to me that some of these more extreme ideas are gaining traction in the country,” Robert P. Jones, the president of PRRI, told me.

Even many in the communities that Trump’s immigration plans would most directly affect appear more focused on other issues. Every major data source on voting behavior agreed that Trump grew his vote among Latino voters from about three in 10 to nearly four in 10 from 2016 to 2020, largely around economic issues, but also because of gains among cultural conservatives. Though the GOP advance among Latinos stalled between the 2020 and 2022 elections, polls continue to record widespread dissatisfaction among them about inflation, which could further erode support for Democrats in 2024.

The Muslim American community is much smaller—Muslims account for only about 1 percent of the total U.S. population—so reliable information on its voting behavior is less available. Youssef Chouhoud, a political scientist at Christopher Newport University, told me that Trump’s vote among Muslim Americans nationwide improved from about one in six in 2016 to roughly one in three in 2020. Key to those 2020 gains, he said, was sympathy to conservative GOP arguments on issues such as LGBTQ rights and discussion of sexual orientation and gender identity in schools.

Now, Chouhoud and others note, those Republican gains are being reinforced by the backlash among many Muslim activists against Biden’s expansive support for Israel in the conflict with Hamas. Waleed Shahid, a Muslim American Democratic strategist who has worked for several liberal groups and candidates, says that leading Democrats are underestimating the visceral anger over Biden’s words and actions. “I think, unfortunately, Democratic leadership has their heads in the sand about this,” he told me.

Both Chouhoud and Shahid told me they believed that Trump’s return to anti-Muslim rhetoric reduces the odds that any significant number of voters from that community will abandon Biden to vote for the former president. But they both said they considered it likely that some Muslim American voters disillusioned with Biden might stay home or drift to third-party candidates. “The fact that this chorus” in the Muslim community “is so loud” in criticizing Biden, “even given the full knowledge” of Trump’s bellicose rhetoric, “is telling you that there is a groundswell of real animosity toward the policies that the Biden administration is enacting right now,” said Chouhoud, who is also a fellow at the Institute for Social Policy and Understanding, a nonpartisan group that studies issues concerning Muslim Americans. This discontent could matter most in the swing state of Michigan, where Muslims are a sizable constituency: A mobile billboard drove through the Detroit area this week displaying a message proclaiming that “Israel Bombs Children” and “Biden Pays For It.”

Shahid says he fears that the 2024 election won’t look like 2020’s—when Democrats of all stripes unified behind the common mission of ousting Trump from the White House. Instead, he thinks, the next election will more closely resemble that of 2016, when a decisive sliver of Democratic-leaning voters, particularly younger ones, backed the third-party candidates Gary Johnson and Jill Stein rather than Hillary Clinton.

“The Democratic base did not turn out for Hillary in 2016, even though Trump was a right-wing extremist,” Shahid told me. “People somehow have collective amnesia about this. But Biden is historically unpopular with the Democratic base.”

Of course Biden may regain Muslim voters’ trust if he can jump-start renewed negotiations between Israel and the Palestinians after the fighting concludes. Similarly, very few Latinos may now be aware of Trump’s proposals for mass deportation of undocumented migrants and military action against Mexico; if he’s the nominee, that would likely change—and prompt substantial resistance, especially among Mexican Americans.

Still, these tensions reveal a larger dynamic underpinning the potential 2024 rematch between the two men. On almost every front, Trump has formulated a 2024 agenda even more confrontational to Democratic constituencies and liberal priorities than he pursued during his four years in the White House. Yet disenchantment with Biden’s performance could be eroding the will to resist that agenda among key components of the party’s coalition, particularly young people and voters of color.

The pressure that the Middle East crisis is placing on Muslim American support for Biden, even as Trump directly threatens that community, shows how hard it may be for Democrats to maintain a united front—even against an opponent whom they consider an existential threat to all that they value.

Even before Bob Menendez was charged earlier this month with conspiring to act as a foreign agent, dozens of his fellow Democrats were calling on him to resign. Prosecutors say Menendez used his political office to influence American policy at the behest of the Egyptian government. He remains a senator—for now—but the latest indictment, coming after corruption charges last month, further complicates his fate. Last week, Menendez, who has pleaded not guilty to all counts, missed an all-senators classified hearing on Israel—no small indignity for a former chair of the Foreign Relations Committee.

According to the indictment, the senator from New Jersey passed along sensitive information to Egypt, acted as a ghostwriter for its officials, and accepted “hundreds of thousands of dollars of bribes.” While researching my next book, a history of the foreign-lobbying industry in the United States, I didn’t come across anything quite like these allegations. They appear to be the first time that an elected federal official has been formally accused of acting as an agent of a foreign government.

Menendez has repeatedly professed his innocence and his loyalty to America. After his arraignment earlier this week, he released a statement calling the foreign-agent charge “as outrageous as it is absurd.” His trial is set for May, when Menendez says he’ll be shown to have done nothing wrong.

[Read: Why this time is different for Bob Menendez]

Even if the allegations are disproved, however, they could reshape how America prosecutes and punishes the kind of misconduct that Menendez is charged with. Until recently, the U.S. has largely ignored its best tool for deterring covert foreign agents. The case against Menendez signals an overdue willingness to use it.

Menendez’s alleged behavior might be novel, but we were warned of its possibility centuries ago. The Founding Fathers recognized that, in some ways, America is particularly vulnerable to foreign influence. “One of the weak sides of republics, among their numerous advantages, is that they afford too easy an inlet to foreign corruption,” Alexander Hamilton wrote in The Federalist Papers. The danger may be greater today: Underpaid and overworked, U.S. officials are ripe for targeting by foreign powers eager to sway decisions in Washington. History, Hamilton noted, “furnishes us with so many mortifying examples of the prevalence of foreign corruption in republican governments.” Why would the U.S. be any different?

For years, these concerns appeared overblown. (Though not entirely: James Wilkinson, who served as the highest-ranking officer of the U.S. Army under each of the first four presidents, was revealed after his death to be an agent of the Spanish monarchy.) Then came the 19th century’s greatest foreign-corruption scandal.

In the late 1860s, Russia’s czarist regime was broke and desperate to sell Alaska, its easternmost province. So the Russian ambassador, Edouard de Stoeckl, secretly hired former U.S. Treasury Secretary Robert Walker to persuade Washington to buy it. Walker quickly obliged, publicly endorsing the purchase, planting articles in influential newspapers, and allegedly—no hard proof ever emerged—bribing legislators. Within a matter of months, Congress voted to back the purchase. When the details of Stoeckl’s gambit later spilled out, one critic described it as the “biggest lobby swindle ever put up in Washington.”

Walker’s offenses were shocking, but at least he had the decency to leave office before committing them. This sets him apart from the precedent that Menendez has now allegedly established. A more recent case, however, comes close.

In 1999, nearly 50 years after his death, Representative Samuel Dickstein of New York was revealed to have been a Soviet agent. KGB archives showed that Dickstein used his office to grant Soviets access to U.S. passports and, in one instance, to pass information about a Soviet defector who was later found dead in a hotel room.

Unlike other Americans recruited by the Soviet Union, Dickstein did not appear to have communist sympathies. Rather, Dickstein—whom Soviet officials nicknamed “Crook”—seemed interested only in money. “‘Crook’ is completely justifying his code name,” Soviet officials wrote. “This is an unscrupulous type, greedy for money … a very cunning swindler.” The Soviets eventually cut him loose, complaining that he wasn’t worth the price he demanded. Dickstein was never found out and spent the rest of his life in public office.

[Read: How the Manafort indictment gave bite to a toothless law]

The revelations were all the more surprising because Dickstein played an instrumental role in passing the Foreign Agents Registration Act, or FARA, America’s best safeguard against people like himself.

In the 1930s, he led a committee that found that Ivy Lee—sometimes called the “father of public relations,” whose clients included the Rockefellers, Woodrow Wilson, and Charles Schwab—covertly advised the Nazis, helping them launder their image in America. At one point, Lee encouraged Joseph Goebbels to cultivate foreign reporters; he told other Nazis to publicly insist that Hitler’s storm troopers were “not armed, not prepared for war.” (One unsigned memo I found in Lee’s archive described Hitler as “an industrious, honest and sincere hard-working individual.”)

Thanks to these and other revelations, Dickstein and the committee played a key role in persuading legislators to pass FARA in 1938, which required anyone representing foreign governments, especially lobbyists, to disclose what they were doing on behalf of their clients. Dickstein is the only known member of Congress to violate the law he helped enshrine.

According to prosecutors, Menendez largely followed Dickstein’s playbook—passing along sensitive information, steering American policy for the benefit of foreign patrons, and accepting staggering amounts of money for his efforts, including in the form of gold bars.

The fact that prosecutors employed FARA to charge Menendez is a welcome development. The legislation was underused for decades, as foreign-lobbying networks—including those targeting sitting officials—flourished. To cite one statistic: Only three FARA-related convictions were secured from 1966 to 2015.

That wasn’t for lack of rule-breaking. A decade ago, Azerbaijan’s dictatorship and its proxies recruited American lobbyists, scholars, nonprofits, and others to promote Azeri interests without disclosing any of their campaigns. Other dictatorships and budding autocracies followed suit. As one 1990 government report found, barely half of registered foreign agents disclosed all of their activities.

When Donald Trump emerged as a political force, FARA experienced something of a renaissance. Although the former president was never accused in court of acting as a foreign agent, some of his closest allies—including his campaign manager Paul Manafort and National Security Adviser Mike Flynn—were convicted on related charges. (Trump later pardoned them both.) But those prosecutions never targeted a sitting official. That honor belongs to Menendez alone.

The renewed interest in FARA has highlighted the ways in which the legislation can be improved. The legal definition of foreign lobbying needs clarifying, and the Department of Justice should be empowered to use civil fines (rather than just criminal penalties) to target covert networks. Effective reforms have been proposed, but they’ve stalled in Congress. As Bloomberg Law reported, one legislator in particular was responsible for thwarting them: Menendez.

If proven guilty, Menendez will come to represent the culmination of the Founders’ fears—perhaps the most “mortifying example” of foreign corruption in U.S. history. But whether or not he’s convicted, Congress could use the attention his case has drawn to strengthen FARA, keep foreign lobbying in check, and give would-be offenders more reason to fear concealing their activities. If the charges against Menendez are a black mark, they can be a turning point too.