Certainly a valid concern, which is why it was so unfortunate Obama reneged on his earlier pledge to use public funding for his campaign rather than relying on private sources which now turn out to have included quite a few made-up people. Similarly, I think it's reasonable to care about any candidate's friends and role models - there was at least some justification for people's interest in that wacky "guru" woman Tony Blair's wife was spending time with, although less so than if it had been the PM himself doing the same thing.