I don’t think I’m with brother Geraghty on this.
It’s true, as he says, that “Candidate X shouldn’t be president” implies “Candidate X’s backers are wrong.” But it need not imply “backers are bad, stupid, or have poor impulse control.” And in any case an implied point can be left implied.
Turning to the specific case, attacking Trump backers does not seem like the course best calculated to help produce a conservative majority. I think the better approach for Trump critics would be a) to condemn what needs to be condemned in his record, views, and actions; b) to try to see why some basically good and intelligent people like him; c) to make the case that backing him won’t achieve anything worthwhile; and d) to relax a bit about Trump and even his less-reasonable supporters, since Trump seems highly unlikely to be the Republican nominee. One headline on NRO a while ago was “Rick Perry Compares Trump to Cancer, Know-Nothings, and Joe McCarthy in Double-Barreled D.C. Speech.” I vastly prefer Perry’s politics to Trump’s. But let’s not get carried away: The guy isn’t the government of Iran.
All of that said, anyone who thinks it is true and important to say that Trump’s fans are bad, stupid, etc., should go ahead and say so, and let the political consequences fall where they may.