Generically, a POTUS Democrat means a chance at unstacking the court.

It doesn't matter what your politics are, one of the branches of government being severely unrepresentative leads to instability.

I'll put this out there in the hopes that someone can argue the other side: the mechanism by which supreme court justices are appointed is inherently broken. Because they serve for life, a few bad rolls of the dice (one party is afforded fewer chances to appoint), coupled with the ability of the Senate, which is by design unrepresentative, to stonewall any nomination, means given enough time we're guaranteed to have a stacked court.