Make a derogatory statement about the intelligence of people who identify as left-leaning or liberal.
I always wonder at the Stupidity of the Lefties.  They claim to be "educated" but they are really brainwashed.  The Lefties are so stupid they cannot even do basic math.  They demand high wages and low costs - this is just one way their stupidity shows there are many other ways it would take me days to list.