In the days after January 6 2021, when Donald Trump supporters stormed the US Capitol, House Republican leader Kevin McCarthy said the then president bore “responsibility” for the attack and chastised him for failing to denounce the mob. Just two weeks later, however, McCarthy posed for a smiling photo with Trump at his gilded Palm Beach resort. Trump called their meeting “cordial”, and vowed to work with McCarthy to help the Republicans achieve a majority in the House.

Now, on the eve of US midterm elections, opinion polls suggest the Republicans are poised to do just that. If they do, McCarthy will probably be installed as Speaker of the House, succeeding Nancy Pelosi. That would make the 57-year-old arguably the most powerful Republican in Washington.

Like other Speakers before him, McCarthy will need to wrangle a raucous band of lawmakers; former Speaker John Boehner once likened the job to keeping “218 frogs in a wheelbarrow long enough to get a bill passed”. McCarthy is expected to take the gavel at a time of unprecedented partisan rancour, with Democrats still livid about January 6, and Republicans wrestling over their party’s future. He will also need to navigate “divided government” and decide whether to work with Democratic lawmakers and the Biden White House — or against them. McCarthy has already threatened to use raising America’s debt limit as leverage to force domestic spending cuts and withhold additional funding for Ukraine.