Lee Iacocca had two big failures at Ford before he hit a home run with the Mustang.
For 1956, he was instrumental at convincing Ford to emphasize safety (seat belts, padded dashes, and deep dish steering wheels) rather than performance. Chevrolet killed Ford with their "Hot Ones' advertising campaign.
Then he pushed the use of marketing research to show how great the Edsel would sell. Unfortunately, the use of Statistics and polling was in it's infancy, and the Ford researchers didn't realize how many of the people who were being samples were saying what they thought Ford wanted to hear rather than what they really thought of the cars they were being shown. Granted, there were other factors to Edsel's failure, such as the nations first post WWII recession, but as far as Ford was concerned it was Strike2 for the hot young executive.
In 1962, marketing research techniques were much improved, and Iacocca once again suggesting using previews of the new Cougar (it was renamed Mustang before going into production). Ford still distrusted the marketing research to the point that in 1963 the company took a preproduction Mustang convertible and had it chopped and customized, named it the Mustang II and sent it to several auto shows and racing events. The public's and media's reaction was so positive that Ford execs began to believe Iacocca's marketing data and gave the Mustang the go ahead. But the execs made it VERY clear that it was Iacocca's LAST chance.
So you see, Iacocca had a LOT to do with the Edsel.