Late Upsets Are Rare, but Have Happened
There have been only 2 instances in the past 14 elections, from 1952 to 2004, when the presidential candidate ahead in Gallup polling a week or so before the election did not win the national popular vote: in 2000 (George W. Bush) and 1980 (Jimmy Carter). And in only one of these, in 1980, did the candidate who was behind (Ronald Reagan) pull ahead in both the popular vote and the Electoral College and thus win the election.
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