birtherism

noun

1. (US, derogatory, often, slang, uncountable)A movement in the United States of America that doubts or denies that the 44th President, Barack Obama, is a natural-born U.S. citizen, thus implying that he is ineligible to be President.

   “But Obama's plunge into the fever swamp of birtherism was just the latest detour on what had already been a long, strange trip—with many miles still to go.”