Somehow trying to equate love for Trump when he gets prosecuted with Dems' love for Biden when he is portrayed as mentally deficient is...something. One, I don't think Dem voters react that way at all to news about Biden's mental state (poll data is really noisy). Two, most would already like someone other than Biden to be the nominee for exactly that reason. It's getting from point A (wanting someone else) to point B (unifying the party behind a candidate better than Biden) that is hard. The thing that makes Dems (and a lot of independents) determined to vote for a turnip over Trump is the fact that Trump deserves prosecution for the things he's done. That's why Haley crushes Biden in the polls. And yet every time you are given the opportunity to criticize Trump on this stuff, you rally to his defense and blame the Dems. That's why Haley isn't going to win the nomination.