Honestly, the problem is far less the Democratic parties fault, although of course, they bear some fault, then it is the destruction of news that pretends to be objective.
Having spent at least seven decades on this planet, it is my opinion that we have essentially the same amount of uneducated gullible mooks as we ever did. What we did not have are supposed news outlets like Fox News spreading completely false news to injure one political party while completely ignoring the broadcast of news problematic for their preferred political party.
And while I get that people will depend on Facebook and their friends and family for some information, it was Rush and the GOP who convinced a large part of the country that there is absolutely no true fact to be gleaned by reading the Washington Post or New York Times or any newspaper that is not MAGA supportive. I grew up watching the news in the 60s and the objective facts in the ABC NBC and CBS nightly shows did not vary that much in content. They more or less gave straight news reporting and then people argued about what the facts meant. There were no such things as alternative facts. THAT situation is the most damaging. Once you convince a large portion of America that they are a disloyal non-patriot if they receive news from anywhere but the Dear Leader’s source, there is nothing a democrat can say on a stump speech or commercial that will penetrate through that thick steel curtain of stupidity.
When people talk about the better talking points that Democrats could make, they gloss over the fact that a third of the country will never see that point - or if the commercial starts to come on - they will turn the channel or start talking transgender operations during the rest of it. Advocating for better messaging is obviously a great thing, but it seems to ignore that one side has made it a religion not to listen to or believe that messaging, be it better or not.
That in my opinion is the bigger problem. A third of the country totally embraces self-induced voluntary ignorance of the other side’s alleged facts. Until that changes, there is very little that the Democrats can do except wait for the GOP to run the country so far in the ground that they look for an alternative.