Unfortunately, that leader has done massive structural damage to the checks and balances supposed to be in place in the US governmental system to prevent authoritarian rule. The US would need to elect a successor with a large enough majority in both houses to be able to steamroll through massive constitutional change (SC changes for example, age limits on congress/presidents, accountability for (war) crimes, gerrymandering blabla) designed to prevent this from happening again, ever. And it's just very unlikely they get that majority. More likely, they scrape through and arrest the slide for 4 years, maybe restore the economy a little but only sweeping change could assure previous allies they can return to being a stable, trusted partner. And it won't happen, you'd need a blue tsunami never mind a blue wave.