While I'm not sure I'd use the word "absurd," arguing that "he won, so it couldn't be absurd to support him" doesn't make sense. Lots of demagogues win elections. Winning an election doesn't automatically make you ethical or competent.
Sure it is, if there's a 30%/70% split of viewpoints then the 30% viewpoint is a mainstream viewpoint as well, not some weird niche - it's also considered normal and conventional (though less popular than the 70% one), shared by a significant part of the people, known / acknowledged by almost everyone including the opponents.
