If the executive branch changes hands, I would be willing to bet money that the Supreme Court will immediately do a 180 and declare all of these things as no longer powers of the executive branch.
All of the things that were perfectly OK for Trump to do will suddenly be off limits for a Democrat president.
It's also not at all clear that they intend to let the White House change hands again. One would assume that they have all the power they need to make that happen, and why wouldn't they?