Roosevelt ran as a third party candidate and won. It doesn't matter that he was once on the Republican ticket. He wasn't the incumbent, and though he was popular with the public, he had no republican support (other than what he got from those who just didn't like Taft). He started a party, went to primaries and caucuses, campaigned hard, said (and did) a lot of radical, crackpot shit, and won. I think you drink too much Republicrat Kool-Aid.
Are you talking about the 1912 election? Because... he didn't win he just defeated Taft. Taft got 8 electoral votes to Roosevelt's 88 to Wilson's 435. He didn't win he just beat one of the two major parties by splitting their party, essentially, in half. Also, he did this out of a concern that Taft had become too conservative.
All of that is beside the point; this isn't 1912 and we're not talking about candidates who held the Oval Office twice. We're also not talking about candidates with enough charisma to cause a schism in either major political party. We're talking about people dismissed by the establishment (Both major political parties, the media and blogosphere, and the public at large), running repeatedly and losing, being "protest votes."
A third party isn't impossible and simply voting third party isn't necessarily a waste. However, given who the third party candidates are (and have been recently), it seems like a vote out of protest against the establishment to cast for someone who has zero point zero zero zero chance of winning and that I believe was her point.
If the word "ignorant" is going to be tossed around I'd like it applied to the notion no one has access to wikipedia.
JSZ