Are Swing Voters Stupid?

Swing voters, so goes the conventional wisdom, decide presidential elections.  Especially close presidential elections.

Especially this presidential election.

But swing voters, argue some, are the least politically knowledgeable.  In trying to explain Obama's success (so far) against Romney, this essay, published Monday by Ilya Somin, posits:

Some of the models also take account of foreign policy events. While one can certainly make a case against Obama’s foreign policy, he has not presided over a large and obvious failure that can clearly be laid at his door in a way that swing voters – most of whom have very low levels of political knowledge – can readily grasp. 

Note that phrase:  readily grasp.  This is a small part of the essay, which really gets into whether or not Obama is "overpowering historical expectations" by being ahead in such lousy economic times.

The older piece (linked to in the quote block above), examines whether "independent-independents" are the least knowledgeable. Set aside for the moment this all confuses independents with undecideds.  Below, I ran some quick numbers using national survey data I'm presently fooling around with.  It's political knowledge on a 4-point scale, ranging from 0-to-4, by partisan identification.

As you can tell, partisans know more, independents less.  There's no statistically significant difference between strong Democrats and strong Republicans (the far left and far right on the scale), or between weak Dems and GOPers.  You do see a difference between the leaners, for what that's worth.  Give the GOP an edge there, mostly explained by education.
 
Keep in mind it's an open question whether the kind of knowledge we measure in such surveys really matters when it comes to voting your own particular interest in a presidential election.  I suspect even someone who performs poorly on such tests can manage to figure out which candidate may govern in their best interest.  They may not be able to put it in words, or at least the kinds of words that will impress political scientists and law professors (or journalism guys like me), but my hunch is many of these independent-independents, despite doing poorly on our political tests, feel they can vote just fine, thank you very much, by broadly perceiving the differences between the two parties or the two candidates.