Well, in fairness, I think most of these people have -- through simple osmosis -- learned more about the two candidates than they probably knew about what they were signing.
There's a lot of economic theory about how it may be possible for uninformed actors to make "good" decisions -- that is, the decisions they would have made had they been fully informed. Interesting stuff.
Still, it's just the image of these slackers, who probably don't give a rat's ass about politics, finding out that they've signed up to be Republicans, that makes me laugh.