Yeah, that's exactly much what I was thinking, that when you take a look at their activities, it's clear that the definition of what's considered political here

Yeah, that's exactly much what I was thinking, that when you take a look at their activities, it's clear that the definition of what's considered political here is fairly narrow. Re: your hypothesis, after learning about 501c4s from Jeff in this thread and reading about for 10 seconds on Wikipedia, it seems that those actually serve that purpose quite well ("super PACs" are apparently 501c4), so I don't think the 501c3s are highly likely to get used in that way.