I've mostly made peace with there being a chunk of his base that will love this shit.
The people who buy merch like this. The people who've been on board for a long while won't let this shake them, because as gross as the tape is nothing he said here is surprising or out of line with who everyone knows Trump to be. We've heard him on Stern, we know his history, he's a man who says vile things because he's some level of rich and famous and can get away with it.
All this needs to do, and all the next month needs to focus on, is constantly reminding the people who were drifting Trumpwards because they were staunch GOPers "coming home" that the man himself is repugnant, and not let them turn a blind eye to who they're voting for.
This won't send Trump plummeting in the polls, but it doesn't have to. He's losing. As long as it makes it harder for people to swallow Trump in the name of the Supreme Court, he'll stay losing. This won't knock him out of the race in an immediate fashion, but it's going to keep him down and send anybody with a reputation to defend scurrying to distance themselves.