Now there's proof: Trump's voters lack "cognitive sophistication," often believe Bible is literal word of God
www.salon.com
then it would seem to me that the best tactic would be to "dumb down" the democratic rhetoric for republicans...tell them the truth, but make it bite size...truth mcnuggets...use logical progression chains with small steps to lead them to the right conclusions.
start small, maybe something like " There is a .01% difference between all humans alive on the planet today. the physical differences are actually adaptations to environment, and do not contribute to "racial" differences, which are so rare and so minute that they are statistical anomalies, adding up to .01% of genetic differences world wide." but presented at a 3rd or fourth grade level, with simple animations designed to be kind and happy looking...Sesame street for adults...
with a little of my personal favorite, which still makes me laugh like a fool and walk around going "Book, Book...nope, nope..."
and occassionally "BARrring..."