"Blame" here implies being mentioned as a contributing factor to the loss. I will resolve this as true if either of the two typical party candidates includes negative mention of a third party candidate specifically or third party candidates in general during a classic concession speech. If there is no such speech, it will be resolved as false. If a third party candidate happens to blame some other third party candidate in their concession speech with the implication their candidacy cost them the White House, I will resolve as true.