This is truly pathetic. What's really sad here is that, as Polman points out, it takes almost no effort to find out at least the bare minimum about candidates and basic information about them. (In these folks' worldviews, also, McCain is a "maverick" and probably some sort of "moderate"...)
I think part of this stems from the annoying and misguided but well-intentioned efforts of officially neutral civic patriots who, every election cycle, emphasize the importance of voting. The importance of voting, yes - but what about the importance of having the first idea about the person you're voting for?