What Biden needs to do if he wins and Trump is dealt with, is to use his four years to lead a charge to completely dismantle the presidency in its current form. It's way too powerful with very little accountability. He keeps talking about being a transitional figure. Well that would be a transition. Away from having an elected, time-limited kingship back to an actual presidency. Get rid of the Patriot Act. Abolish the filibuster (Yes, that's a Senate thing, but he should be clear that he wants it gone.) Don't do anything with Executive Orders that could be accomplished through Congress. Dismantle the "National Security" apparatus. DHS has to go. Put some rules around corruption in place. Congress needs to pass laws that make the shit Trump pulled the last four years illegal, instead of just frowned upon. I would also like to see an easier way to remove an incompetent executive from office.
I know it's a lot, and that's not even an exhausitive list, just the biggest fires. Apart from shoring up democracy for the next generation, he also needs to deal with climate change, corona virus, police brutality, racial & economic inequality, voting rights (fuck the Electoral College!)… The list goes on. It's too much for one term, but without curtailing the presidency at all, the gains Biden and his team could make, might be gone again after the next cycle. Just look at Obama's legacy. Thinks have to be codified into law or they will go away again. (See Obamacare. Sure, it was gutted severly, but Republicans couldn't get rid of it for good, because it's the law.)
I also know that almost no one gives up power willingly, but I worry. If Trump can be removed from office peacefully (which is a big if, November is going to be hell for all of us), who's to say that the next white supremacist elected to office isn't marginally more competent and completes the road to authoritarianism? The American presidency as it stands is too dangerous to exist. Period.