Why did George H.W. Bush lose in 1992?

[Pericles]

Bush's approval rating was in the toilet by 1992. Fundamentally that was the economy doing him in, and while the read my lips debacle and the campaign didn't help an incumbent President (especially one running for a fourth term of their party) with the economy Bush had wouldn't win. If foreign policy had remained a big issue, like if the war in Iraq had continued until after the election Bush may have been able to survive but the economy meant he started at a disadvantage. Perot may indeed have been a spoiler in his favor given the strength of opposition to him and how Clinton led by such landslide margins when Perot was out of the race(a 1999 study suggested Perot reduced Clinton's margin by 7 points, though that seems excessive)-though indeed he may have just had no major effect given the exit polls said Perot voters split evenly between Bush and Clinton(38-38). Bush may have lost by less against a different Democrat or if he'd run a better campaign, but his loss was both pretty substantial and to be expected based on the fundamentals so most scenarios would probably have him losing.