President-elect Joe Biden will face many formidable challenges when he assumes office in January. One of the first obstacles that Biden must overcome after Inauguration Day is getting the Senate to approve his Cabinet, the top government officials who will help the new president implement his agenda over the next four years.

Democrats and Republicans agree that Senate Majority Leader Mitch McConnell is Biden’s chief adversary in the looming fight over his Cabinet. They contend that McConnell will have the power to veto Biden’s Cabinet picks if his party holds on to its Senate majority next year and if he remains its leader. Sen. Chris Murphy, a Democrat from Connecticut, said he expects that McConnell will use his veto power to compel Biden “to negotiate every single Cabinet secretary, every single district court judge, every single U.S. attorney with him.” Republicans predict that McConnell, who has not yet acknowledged that President Trump lost the election, will veto Biden’s picks if he believes them to be “radical progressives,” deems them “clearly unqualified,” or otherwise suspects them to have “ethical problems.”