The only accurate way I can imagine to measure the electability of a Black woman is to let her run.

But the same is true about a somewhat mentally diminished president. If not mentally diminished, his ability to communicate off the cuff seems alarmingly worse.

As to your last point, my imagination substituting JFK, LBJ, Nixon, Reagan, Clinton or Obama for Biden in that last debate works out well against Trump. Any of them would have bowled over a loud but obvious liar.

But beyond all that, as a long-term professional politician, Biden should have known not to be jet lagged, take Benadryl, or whatever. From his interview with Stephanopoulous, he’s not sure he’s watched the debate (?!) and didn’t seem to be aware how bad he did.