I'm just interrogating your statement. Yes, oppositional propaganda is a known phenomenon. It isn't new. If you are campaigning for election, your job is to overcome it somehow and win. Harris wasn't lacking funds and she had the (arguable) advantage of running from an incumbent administration, as well as the advantage of running against a clown like Trump.

There were loud and numerous warnings to and criticisms of her campaign from the left. She ignored that. I can't prove that's definitely what cost her the election, but there is no question that she could have run a very different campaign. Blaming her loss on propaganda is weak and defeatist. Find ways to win, not excuses to lose.