DETROIT (AP) — Only a couple of weeks after Barack Obama won the presidency in 2008, the man who would become his Republican challenger in the next election penned a New York Times column with a fateful headline: "Let Detroit Go Bankrupt."

Those four words would haunt Mitt Romney across the Rust Belt, where auto manufacturing remains an economic pillar — especially in Ohio, a state that every successful GOP presidential nominee has carried, and in his home state of Michigan, where his father was an auto executive and governor.

Romney's opposition to the federal rescue of General Motors and Chrysler didn't necessarily seal his fate in those two crucial states. But no other issue hung in the background for so long. And nothing that Romney tried — his many visits, the millions spent on ads, his efforts to explain and refine his position — could overcome it.

"The biggest determining factor was that we couldn't handle the automobile bailout issue," said Bob Bennett, chairman of the Ohio Republican Party.

Fairly or not, the perception of Romney as indifferent to the auto industry's fate was "a coffin nail," said John Heitmann, a University of Dayton historian who teaches and writes about the car's place in American culture.