(CNN) — Republicans will win the House of Representatives, CNN projects, in a victory that will fall short of their hopes of a “red wave” but thwart President Joe Biden’s domestic agenda and will likely subject his White House to relentless investigations.

The fact that the GOP finally passed the threshold of 218 seats needed for control of the chamber eight days after Election Day — and that it came down to the final districts to report results — underscores the party’s underwhelming midterm election performance, which history and political logic suggested should have delivered a heftier rebuke to Biden and Democrats.

In defiance of political gravity, Democrats held onto the Senate after an election dominated by concerns about high inflation and influenced, in some places, by the Supreme Court’s overturning of a constitutional right to abortion this summer. There’s still an outstanding Senate race in Georgia, which will be decided by a December runoff and will determine how large Democrats’ majority will be.

Republicans’ victory in the House will end Democrat Nancy Pelosi’s second tenure as speaker in January. But its majority looks set to number a handful of seats, far short of initial expectations in a margin that will make managing a restive Republican conference a stiff task for party leaders.

And while less impressive than party leaders had hoped for, it still represents a return of Trump-style ideology and chaos politics to Washington, given the strong influence the ex-president is likely to wield over his acolytes in the GOP conference. The former president announced his 2024 presidential bid on Tuesday night.

The new Republican-led House is certain to make life decidedly miserable for the White House for the rest of Biden’s term, as the president admitted before the election when he told reporters the loss of the Democratic majority would make things “more difficult.”

Republicans will be able to activate their plans to target the White House, the administration and the president’s son, Hunter, with a relentless slate of investigations. Given the reality of divided power in Washington and Biden’s veto, the GOP will struggle to force its own agenda into law. But it may act as a political weapon for Trump by trying to damage Biden ahead of their possible 2024 rematch.

In an exclusive interview with CNN before the election, House Minority Leader Kevin McCarthy pledged to prioritize the fight against inflation, rising crime and border security.

“The first thing you’ll see is a bill to control the border first,” the California Republican said, when asked for specifics about his party’s immigration plans. “You’ve got to get control over the border. You’ve had almost 2 million people just this year alone coming across.”

A smaller-than-expected Republican majority could create volatility in the conference by handing more influence to extreme, pro-Trump backers. The challenging job of managing the conference will require McCarthy to placate more moderate members whose seats will be most vulnerable in 2024 and who could fracture his governing majority on individual legislation if they defect to vote with Democrats.

In a news conference the day after the election, Biden offered to work with the new Republican majority. But he ruled out compromises on his priorities, including any effort to downsize Social Security and Medicare and to abandon his ambitious climate change goals.

In practice, that probably means that room for cooperation is limited. And given the sway extreme members are likely to have in a narrow GOP majority, there may be little appetite for cooperating with a Democratic White House anyway.

Divided government is likely to cause a series of showdowns between the Republican House and the Democratic White House over tax policy, spending and even the extent of US aid to Ukraine.

The most dangerous potential clash could come over the need to raise the US government’s borrowing ceiling sometime. Republicans have vowed to demand steep spending cuts in return for voting for legislation on the issue, a stand that will spark criticism that they are holding the global economy hostage for political reasons. Failure to lift the debt limit would cause the United States to default on its obligations, throw the economy into a deep crisis and would cause global contagion. Controversies such as these will test McCarthy’s leverage over his coalition. Two of his predecessors, Speakers Paul Ryan and John Boehner, were driven to distraction by trying to deal with their most radical members. McCarthy’s task is likely to be even more complex given Trump’s influence with House Republicans and his desire to wound Biden politically.

The House Republican conference voted for the California Republican to be its leader on Tuesday, putting him in line to be the next speaker. He defeated longshot challenger Rep. Andy Biggs, a former chairman of the right-wing House Freedom Caucus. The Arizona congressman received 31 votes to the California Republican’s 188, according to multiple sources in the room. It was a secret ballot and McCarthy only needed to earn a simple majority of the conference. In January, McCarthy must win 218 votes, or a majority of the House, to become speaker.

But while the votes against him underscored the turmoil in the party after the GOP’s underwhelming performance last week, McCarthy enjoys significant support in the wider Republican conference, because of his prodigious fundraising, energetic campaigning and years of preparatory work designed to realize his ambition to be speaker.

For instance, Rep.-elect Michael Lawler, who defeated the chairman of the House Democrats’ campaign arm in a New York district, told CNN’s Erin Burnett last week said he would back McCarthy, citing his help during the campaign.

“He was extremely supportive. He came to campaign with me and for me and I am a big believer in sticking with who brought you to the dance,” Lawler said.