People have to think this through, is he in a declining mental state? Most likely, but the next choice is most likely worse.

There's no way to force him to test, all that can be done is raise questions, or the 25th amendment, which again, puts Harris in the big chair.

Most likely best path at this point, is ride out til 2022, hope R's win back House and/or Senate to stalemate Biden through 2024, then both parties hopefully put up viable candidates and we have a good election where you don't have to hold your nose to vote the best of the piss-poor choices.