This article is part of The D.C. Brief, TIME’s politics newsletter. Sign up here to get stories like this sent to your inbox. Joe Biden is in the midst of an incredibly consequential stretch of his presidency and remarkably little of it will be under his sole control. In fact, much of the coming weeks—and, perhaps, months, if not his total legacy—is contingent on the engagement of other players and their openness to being good-faith collaborators, and just dumb luck. It is precisely the worst imbalance of power that any White House can face.