This Isn’t a Game
The Assassination of Charlie Kirk, and the Irresponsibility of Being a Political Party with No Platform
The Democrats haven't had a platform since 2016.
They watched Trump win the 2016 US Presidency with shock. They then set about railing against Trump with everything they had. Meanwhile, the news media, who just a couple of years ago was on death's door, saw a large uptick in engagement due to reporting and reacting to Trump's actions and comments.
The Democrat leadership also saw enormous engagement with "being appalled" with Trumps actions and comments. And so, both the news media and the Democratic party kept at it for years. It was good for business.
The Democrats had a solid three years to come up with a 2020 candidate. They instead spent all that time complaining about Trump. When it was time for a 2020 candidate, they pushed someone forward whose cognitive difficulty was already clear to many people.