Here’s another from the same linked post (at bottom):
Leftism is stupidity because when, with the passage of time, the leftist ideas prove as wrong-headed, damaging, disastrous or barbaric as they inevitably do, only very stupid, or corrupt, people remain leftists.
We see this time and time and time again, as ideas that were tried and found to be horribly wrong-headed come back — like some horrid game of Whack-a-Mole — over and over again. Look at Marxism and Eugenics, both enjoying a renaissance of popularity on — where else? — college campuses.