Duel challenge! Democrats should immediately select a Presidential Campaigner Pro Tem (PCPT) to counteract every Trump campaign rally. The party could schedule a counter rally in the same city a little later the same Day before national news or just afterward where the speaker could contradict the lies Trump tells. This speaker must of course be a progressive Democrat but one with a certain look and attitude. He should be a dark haired white male taller and stronger looking and younger than Trump. He should have an impatient, combative attitude toward Trump but respectful to women. He should challenge Trump to turn his campaign rallies into 1 on 1 head to head debates with an audience half selected by himself or his supporters and the other half selected by democrats, progressive independents, even bleeding heart libertarians.
Audience must be screened, strictly divided and both Trump and PCPT guarded, and each allowed to wear light chest armor! Trump and PCPT must be able to get F2F and PCPT must severely challenge Trump, including to a refereed boxing or MMA bout! This is likely to allow PCPT and others to call out Trump as a "Chickeshit Tyrant," etc. Have other 70+ aged democrats in good shape ready to substitute if Trump excuses himself on age.
Sissy Liberal Dem Media (CNN, MSNBC) need to stop repeating Trump's insulting tweets. You are just retweeting him! Muddle his message! Frustrate him! Everybody knows already what a liar and exaggerator he is. On days with his nastiest tweets, leave it to Faux news to state it exactly. Express his content euphemistically. Spend 2-3 time periods a week at news time to unemotionally quote and show exactly what he said. Other times, surround text of his sayings with cutsy jpgs, gifs, hearts & flowers, sappy music. Save strongest criticisms and revelations for hours he is likely to be asleep, so they can burn in when he knows they have been out there for some hours. Establish your own avatars like above to challenge Trump's worst propagandists, a provocateur -- challenger to Hannity, all the way to duke it out, and a woman to bruse the shrew Ingraham.