It's OK
You've just got a touch of Tom-broad-brush-itis.
If I lumped you in with Ann Coulter and Jerry Falwell I'd be wrong.
It just doesn't work when a commentator or comedian has to under-generalize.
"Ya know, the trouble with leftists - barring all of those who think, post on HabitableZone, or otherwise belong to the majority of leftists who call themselves liberals or democrats or even lefties - is they are stupid".
For a comedian, it ain't funny and for a commentator all you got left is less than 1% of the population, and if this's the case there's no use in commentating.
BTW, what you got against Al Franken?
Unlike Michael Moore, he's still funny in a smug (is it facetiously smug, or ironically smug) way.