It's so high, in fact, that Gallup's Frank Newport wanted to see how it compared to the peak unfavourable ratings earned by every candidate back to 1992, when Gallup began tracking the data as it does now.
No candidate in the past 25 years has been viewed more unfavourably by Americans (Democrat, Republican and independent) than Donald Trump.
George H. W. Bush is the only one that really came close, with his unfavourable ratings spiking just before he lost his reelection in 1992. On the most-popular end of the spectrum are Bernie Sanders and Ben Carson -- both of whom are less well-known than Trump, meaning that fewer people have an opinion one way or the other.
There's one small consolation for Republicans worried about an unpopular Trump winning their party's nomination. The third least popular candidate in Gallup's numbers is the person currently leading the Democratic field, Hillary Clinton.