Joe Biden needs to lawyer up. He’s about to see an onslaught of investigations into him, his appointees and their conduct that will now be launched by Republican-controlled congressional committees. It’s not impossible that a Republican-controlled congress could even try to push for his impeachment.

The Republicans squeaked out a bare majority in the House of Representatives this week, with a final tally of 218 Republican seats to 211 Democratic ones. The Republicans performance was abysmal compared to the predictions, with anger over abortion bans and Republican antipathy toward democracy driving voters into the Democratic tent. But the huge structural advantages of being the opposition party in a midterm election, along with some help from gerrymandered redistricting plans blessed by the Republican-majority US supreme court, pushed the Republicans over the top. Now, they are poised to use their new investigatory power in Congress to launch a slew of inquiries into the Biden administration, over matters ranging from the grave to the absurdly trivial.

Biden and his administration won’t need to commit any grave misconduct to attract this kind of official scrutiny over the coming two years. Just being Democrats will be enough; combined with the paranoia and tendency for dark conspiracies that now pervade the American right, the House Republicans are likely to assume that they’ll find something amiss in the Biden world.

Through the House Oversight and Reform Committee, the Republicans are likely to launch a slew of investigations: into the origins of Covid-19 and the lab leak theory; into immigration through the US-Mexico border and the chaotic withdrawal from Afghanistan; and into their favorite topic of conversation, the president’s perennially slimy ne’er-do-well son, Hunter Biden. These inquiries will bloom and multiply, persisting even if they find no real evidence of wrongdoing – like old world witch hunts, or voter fraud investigations after a Democratic electoral victory.

In some sense, this is typical: oversight investigations always ramp up when Congress and the White House are controlled by different parties. But this will not be a divided government like we’ve seen in decades past, with mere gridlock and ineffectualness. This will be messier, more base; it will be degraded, and nationally embarrassing.

The conspiracy-peddling Georgia Representative Marjorie Taylor Greene, a rising star in the Republican party, is reportedly vying for a seat on the committee, giving some sense of the tenor that Republican investigations will take. The Republicans will now embark on a two year public attack on the Biden administration, equipped with subpoena power and the ability to command national attention.

With Speaker Kevin McCarthy desperate to control every member of his boisterous but narrow caucus, it’s likely that the Republican leadership will find themselves obliged to cater to the fringe grievances of even their most extreme members. This means that they will use their House majority to gin up controversies out of minor or imaginary misconduct, to cast aspersions on the honesty and character of Biden and his sympathizers, to suggest malfeasance where there is none, and above all, to create clips that look good on TV – the kind of 10-second snippet that can make a Republican voter angry, and which provide the quick rhythms of a 2024 attack ad.

Biden administration officials are downplaying all this. Some of them told Politico off the record that they think the investigations might even be a good thing for the Democrats. “There is a growing confidence in the White House that the House Republicans clamoring for a hodgepodge of investigations will overreach – and that their attempts will backfire politically, with key voters recoiling at blatant partisan rancor.” “It might make the base feel good,” said one White House ally, “and it’s going to give Matt Gaetz and Marjorie Taylor Greene something awesome to say on their live stream, but it’s not going to be what convinces suburban women in Michigan, Wisconsin and Pennsylvania.”

Maybe the source is right: maybe the Republicans will overreach with their oversight power, the way they overreached with election denial and abortion bans, and voters will be repulsed. But to me, this sounds like wishful thinking – or like the kind of blustering optimism that a politician would project to a reporter in order to keep the public from seeing how screwed he is.

The fact is that the Republicans have long been much more successful than the Democrats at dictating the terms of the national conversation – a disparity in skills that this past midterm cycle has only made more clear. They are bolder and more aggressive; they are almost preternaturally talented at putting the Democratic party on the defensive. The hearings that arise out of these investigations are not likely to be very substantive; they are not likely to be edifying for voters or healthy for the republic. But they’re certain to be good TV.

There are a lot of tasks that Republicans will take up as they assume their majority. They’ll obstruct the Biden agenda; they’ll stymie his foreign policy priorities; they seem determined to hold the national debt hostage in order to force drastic cuts to Social Security and Medicare, the two programs that provide support to America’s elderly. But no one should underestimate their appetite for investigations, no matter how trivial or pretextual the investigations might seem.

When Republicans assume control over the House of Representatives in January, they will form a majority coalition that is even more rancorous and punitive than they were when they last held the chamber in 2018. The Republican party has changed since Trump was forced from office. Some, like Florida governor and 2024 hopeful Ron DeSantis, seem to think that the party is ready to move beyond the cult of personality that it became in the Trump years, ready to pursue Trumpism as an ideology separate from Trump the man.

But the revolution that Trump led within the Republican party is complete. Dissenters have been purged: It’s a fully Trumpist party now, both in the sense of its extremist, anger-driven politics, and in the sense of its shameless bombast and tactical hyperbole. The Republican Congress that will now take power is one that is much less committed to democracy, and much more beholden to baseless conspiracy theories.

Above all, it is a party laser-focused on partisan grievance, in thrall to a base whose identity as Republicans, and whose hatred for Democrats, seems to compose greater and greater proportions of their psychic life. The Republicans – and their core voters – are obsessed with punishment and revenge against Democrats, an obsession that seems likely to persist even after the chastening midterms. We should expect they will use every new power this election has given them to pursue it.

• Moira Donegan is a Guardian US columnist