It's long been a Democratic mantra that grass roots conservatives were racist and stupid. (And this goes back way before the Tea Party movement started.) Personally I've never believed this. Most of of the Tea Party people I've encountered are extremely bright, and I've yet to meet to a racist one. They also tend to be very knowledgeable about politics and the information about science comprehension doesn't surprise me one bit.
My problem with Tea Partiers is not their intelligence nor their identification of political problems: it's that, IMO, their proposed solutions tend to be stringent and worse than the problems themselves. In addition, of course, they are a populist movement, and I don't think such movements generally produce positive results. But I would never question their ability. If they were as stupid as some Democrats paint them to be, they wouldn't be nearly as dangerous as they are.