First, for all the talk of intellectualism that exists on the left, most people clearly do not know what it is. Barack Obama is thoughtful, intelligent, capable, educated, open mined, but NOT, in the purest sense, an intellectual. He is concerned with getting elected, and affecting change. Neither of those are intellectual pursuits, and in fact both--particularly the former--are more often counter-intellectual.
Many people in the progressive movement believe that there is a logical/rational "correct" side on many given issues and that they occupy it, as is evidenced by the abundance of highly educated and intellectual types on their side.
There isn't. There is no such thing as a purely rational/logical position. None. There is always an emotional underpinning.
It is overly simple, but the emotional underpinnings for the generic left and right in this country can be boiled down to: "People have inherent dignity and worth which supersedes their actions," and "People have no value that their actions do not make real," respectively.
If you think that people have great inherent worth, then you probably vote Democrat. If you believe that people make their own worth you likely vote Republican. If you believe that life is more complicated than that, you probably vote for the most competent candidate, you are also in a tiny minority and likely very frustrated by both sides. If you don't even begin to concern yourself with such thoughts then you are one of the group of idiots who are actually swayed by campaign advertisements.