A CNN/Opinion Research poll from April 2010 asked "If you had to choose, would you rather vote for a candidate for public office who is very smart but seems out of touch with average Americans, or a candidate who is in touch with average Americans but does not seem very smart?"
34% chose the smart candidate, 55% chose the one who was in touch, and 11% said they had no preference or weren't sure. The strongest influences on the answers were political preference and self-rated political ideology: Democrats and liberals were more likely to prefer the smart candidate. Among liberal democrats, a little more than half preferred the smart candidate; among conservative republicans, more than 80% preferred the one who was in touch. More educated people were also more likely to favor the smart candidate, but the effect was much weaker.
Some of these differences probably involve reactions to recent Presidents or presidential candidates--even though the question is abstract, people are bound to think "like Barack Obama," or "like George Bush." But the differences are large enough to suggest that there might also be a more general difference in the images of the parties. This particular question was never asked before 2010, but in a later post I'll talk about earlier questions that touch on the issue.