Contrary to the thoughts of a top former Clinton adviser, a University of Iowa analysis suggests that Barack Obama would have gained votes had John Edwards been forced out of the race due to his affair.

On Monday, former Clinton communications director Howard Wolfson said that Clinton would have won Iowa and gone on to the nomination had Edwards been out of the race. He said Clinton and Edwards split the same bloc of voters, largely working class whites, and that she would have received the big share of them.

"Monday's claim from Howard Wolfson that two thirds of Edwards supporters would have supported Clinton is just not supported in data collected directly from those who actually participated in the caucuses," said David Redlawsk, director of the Hawkeye Poll at the university.

"Had Edwards not been running, and if nothing else had changed, my data suggest that Obama would have ended up even further ahead of Clinton than he was."

For more on the caucus survey, www.uiowa.edu/election