First, the claim is incredibly unusual compared to standard political irrationality. The last time this claim occurred was against Chester Arthur (US president 1881) - and John McCain (who was born in the Panama Canal Zone, outside the sovereign territory of the US) received no challenges to his eligibility for office.

Second, the ratio of intensity to plausibility is much higher that most American political irrationality - the long form has been released, after all. This suggests there's more than ordinary political mindkiller at play.