Because they turned a blind eye when their candidate was still in the race and exhibiting obvious and concerning signs of cognitive decline. If they were really concerned about cognitive decline and not just using it to score political points, they'd have intervened much sooner with Biden.
This aired just 5 months ago on MSNBC:
"Start your tape right now because I'm about to tell you the truth, and f you if you can't handle the truth. This version of Biden, intellectually, analytically, is the best Biden ever. Not a close second. And I've known him for years. ... If it weren't the truth, I wouldn't say it."
-Joe Scarborough
Biden swore up and down that he was not dropping out of the race. Right up until the post on X announcing his departure from the race, his own staffers were preparing to hit the campaign trail again that week. Anyone who pretends that Biden just suddenly had an epiphany and dropped out of this race of his own volition is simply not dealing in reality.
I'm curious what makes you say that. Biden often wandered aimlessly, looking very confused. While Trump is a bloviating buffoon, I've seen nothing that causes me to believe that his narcissistic, self-serving rants are any better or worse than they've ever been.
Oh, I'm very concerned. No matter who wins, I'm concerned.
It fascinates me how Harris' approval shot up overnight. I've asked before what Harris has done to merit such an astounding increase in popularity in such a short amount of time. No one seems to be able to articulate why she was able to go from one of the LEAST popular VPs in history to Democratic superstar virtually overnight. Harris' best asset for people seems to be that she's not Trump. I don't know why the Democrats don't just admit that they'd vote for a German shepherd over Trump. Heck, there were people here saying they'd vote for Biden even if he were dead.