I've heard it the other way around, too, and generally from reliable (though not primary) sources. I wonder what the statistics are for those with graduate/professional degrees. Of course, that said, a higher education, especially for those with an MD or JD, correlates rather strongly with higher wealth, which correlates as conservative. As for those in academia, which is what people frequently think of as "the educated," if studies showed that they weren't liberal, I think I'd seriously question their methods. I have no problem agreeing with the statement that college campuses are bastions of liberalism; I just happen not to mind.
no subject