Like you say, stooping to his level will only make things worse.
Democrat party is without doubt too "centrist" if not outright republican lite... Imo for most Americans though that's not really the problem. The problem is that the other side can paint them out to be "Marxist" "commie"etc etc while doing far worse, and democrats are too stupid to properly cal them out for it. The best example of which is the voter fraud/ stop the steal accusations, while literally plotting to use fake electors to steal the presidency..
The best attacks on trump came from his former staff, generals, Arnold Schwarzenegger, for his coup attempt but they barely got any amplitude, I still can't believe the fake electors scheme got so little coverage.. half the reasons people would give for trump were plainly false (peace candidate! Better economy! Fix immigration!) all of these are objectively not true.
At the end of the day, trump only won when going against women, it may be as simple and stupid as that.
We're left to hope that like last time, most of it was just BS to get votes/money from his marks... But there will be real damage to the judiciary and political parties that will eventually lead to civil war imo...
I'm glad I got the out 21 years ago