To be fair, it's hard for the Dems to do anything effectively when a sitting president attempts to overthrow an election, fails, and then half of the voters think "You know what, I want that guy to lead our country again."
Not that they're blameless, of course - they had four years to throw Trump in prison, did nothing, and now we're reaping the result. But the problem goes much deeper than the Dems being incompetent. In a functioning democracy, voters aren't supposed to elect someone who literally committed treason, just because the alternative is "unlikeable" (what the fuck does that even mean, next to Trump).