Donald Trump will begin his second term as president the same way he began his first—with Republicans controlling both the House and Senate.

The GOP scored its 218th House-race victory—enough to clinch a majority of the chamber’s 435 seats—today when CNN and NBC News declared Republicans the winner of two close elections in Arizona. How many more seats the Republicans will win depends on the outcome of a few contests, in California and elsewhere, where ballots are still being counted. But the GOP’s final margin is likely to be similar to the four-seat advantage it held for most of the past two years, when internal division and leadership battles prevented the party from accomplishing much of anything.

Such a slim majority means that the legislation most prized on the right and feared by the left—a national abortion ban, dramatic cuts to federal spending, the repeal of Barack Obama’s Affordable Care Act and Joe Biden’s largest domestic-policy achievements—is unlikely to pass Congress. “I don’t think they’re even going to try on any of those things,” Brendan Buck, who served as a top aide to former Speaker Paul Ryan during Trump’s first term, told me.

[Daniel Block: The Democrats’ Senate nightmare is only beginning]

Trump’s biggest opportunity for a legacy-defining law may be extending his 2017 tax cuts, which are due to expire next year and won’t need to overcome a Senate filibuster to pass. He could also find bipartisan support for new immigration restrictions, including funding for his promised southern wall, after an election in which voters rewarded candidates with a more hawkish stance on the border.

In 2017, Trump took office with a 51–49 Republican majority in the Senate and a slightly wider advantage in the House—both ultimately too narrow for him to fulfill his core campaign promise of axing the ACA. Next year, the dynamic will be reversed, and he’ll have a bit more of a cushion in the Senate. Republicans gained four seats to recapture the majority from Democrats; they now hold a 53–47 advantage, which should be enough to confirm Trump’s Cabinet picks and judicial nominees. The impact on the Supreme Court could be profound: Trump named three of its nine members during his first term, and should Justices Clarence Thomas and Samuel Alito, who are both in their 70s, retire in the next two years, he would be responsible for nominating a majority of the Court.

Yet on legislation, Republicans will be constrained by both the Senate’s rules and the party’s thin margin in the House. Republicans have said they won’t try to curtail the Senate’s 60-vote threshold for circumventing a filibuster. “The filibuster will stand,” the outgoing Senate minority leader, Mitch McConnell, declared on the day after the election. But he’ll be only a rank-and-file member in the next Congress. McConnell’s newly elected successor as party leader, Senator John Thune of South Dakota, reiterated his commitment to the legislative filibuster after winning a secret-ballot election for the role.

How many votes are needed to pass bills in the Senate won’t mean much if Trump can’t get legislation through the House, and that could be a far more difficult proposition. The two speakers during the current Congress, Kevin McCarthy and Mike Johnson, each had to rely on Democrats to get major bills passed, because the GOP’s majority proved too thin to govern. With Trump’s backing, Johnson should have the votes to stay on as speaker when the new Congress convenes in January. (When Trump addressed House Republicans today in Washington, the speaker hailed him as “the comeback king” and, NBC News reported, the president-elect assured Johnson he would back him “all the way.”)

But the Republican edge could be even narrower next year if Democrats win a few more of the final uncalled races. Trump’s selection of Representative Elise Stefanik of New York to serve as United Nations ambassador and Representative Mike Waltz of Florida to serve as national security adviser could deprive Republicans of two additional seats for several months until voters elect their replacements. (Senator Marco Rubio’s expected nomination as secretary of state won’t cost the GOP his Florida seat, because Governor Ron DeSantis can appoint an immediate replacement.)

[Read: Elise Stefanik’s Trump audition]

Still, the GOP has reason to hope for a fruitful session. During Biden’s first two years in office, House Democrats demonstrated that even a small majority could produce major legislation. They passed most of Biden’s agenda—though the Senate blocked or watered down some of it—despite having few votes to spare. And Trump exerts a much tighter grip on his party than Biden did on congressional Democrats. Unlike during Trump’s first term, few if any Republicans hostile to his agenda remain in the House. His decisive victory last week, which includes a likely popular-vote win, should also help ensure greater Republican unity.

“I think we will have a much easier time in terms of getting major things passed,” predicts Representative Mike Lawler of New York, whose victory in one of the nation’s most closely watched races helped Republicans keep their majority. “The country was very clear in the direction it wants Congress and the presidency to go.”

Trump might even hold sway over a few Democrats on some issues. Because Trump improved his standing almost everywhere last week, the House in January will include many Democrats who represent districts that he carried. Two House Democrats who outran their party by wide margins, Representatives Jared Golden of Maine and Marie Gluesenkamp Perez of Washington State, refused to endorse Kamala Harris, while several candidates who more fully embraced the party’s national message underperformed. Nearly all Democratic candidates in close races echoed Trump’s calls for more aggressive action to limit border crossings, which could yield the new president additional support in Congress for restrictive immigration legislation.

[Mike Pesca: The HR-ification of the Democratic Party]

Like most House Republicans, Lawler endorsed Trump, but he ran on a record of bipartisanship and told me he’d be unafraid to defy the president when he disagreed. As a potential swing vote in a narrow majority, he could have more influence over the next two years. Lawler told me Monday that the GOP should heed the voters’ call to focus on issues such as the economy, border security, tax cuts, and energy production. Pursuing a national abortion ban, he said, would be “a mistake.” And Lawler serves as a reminder that enacting legislation even in an area where Republicans are relatively unified, like tax cuts, could be difficult: He reiterated his vow to oppose any proposal that does not restore a costly deduction for residents of high-tax states such as New York and California—a change that Trump supports but many other Republicans do not.

Trump showed little patience for the hard work of wrangling votes during his first term. Now he’s testing his might on Capitol Hill—and displaying his disdain for Congress’s authority—even before he takes office. Though he didn’t endorse a candidate to succeed McConnell, he urged all of the contenders to allow him to circumvent the Senate by making key appointments when Congress is in recess. After he won, Thune wouldn’t say whether he’d agree. Trump apparently wants the ability to install nominees—Robert F. Kennedy Jr. as secretary of health and human services?—who can’t win confirmation by the Senate.

“The Trump world does not give a damn about normal processes and procedures and traditions and principles of the prerogatives of certain chambers,” Buck, the former GOP aide, said. “They just want to do stuff.” The fight could be instructive, an early indication that no matter how much deference the new Republican majority is prepared to give Trump, he’ll surely still want more.