Draw a comparison between how the left perceives terrorism committed by Muslim extremists and the blame placed upon Republicans by a hate-filled individual in a letter, and argue against the idea that all Republicans share the same views as the author of the letter.
When a terrorist who is Muslim screams "Allahu akbar" and commits his violence in the name of Islam, the lefties tell us the terrorist does not really represent Muslims and we must not assume that all Muslims are nasty.  Now here in this letter we have someone filled with hate claiming to represent Trump.  And Fukumoto then extends that to blame all Republicans.  So come on lefties, apply your same logic to this nutcase.  The fact that some idiot invokes the name of Trump does not mean all Trumpers are like this jerk, and certainly does not mean Republicans are like that.