Would Hillary Have Won Iowa Without Edwards?

Former Clinton campaign spokesman Howard Wolfson told ABC News Monday that he believes John Edwards' decisions may have cost Hillary Clinton the Democratic nomination.

His premise: had John Edwards dropped out of the Presidential race in October, 2007, when allegations of his affair with campaign aide Rielle Hunter first surfaced, it is likely Hillary would have won Iowa and ultimately become the nominee.

Bloggers and journalists reacted swiftly to Wolfson's allegation, almost all of them refuting it, including Chris Bowers at Open Left, Nate Silver at 538, Markos at Daily Kos, the Boston Globe, CNN, the Washington Post and the Los Angeles Times.

Most of them place heavy emphasis on the final polling data available on the eve of the January 3 caucuses which found greater support for Obama than Hillary as a second choice candidate.

Some also rely on caucus entrance polling data and others refer to later election results in other states.

These writers ignore the key premise in Wolfson's statement. He is addressing what would have happened had Edwards withdrawn from the race when the allegations about his affair with Rielle Hunter first became public on October 10, 2007.

What if rather than making a public denial of the charges the following day, Edwards instead admitted the affair and dropped out, leaving only Clinton and Obama as top-tier candidates for the ensuing two and one-half months? According to Wolfson, that scenario would have resulted in Hillary winning Iowa by the time caucus day came around.

In attempting to assess the validity of Wolfson's belief, I don't find the final pre-caucus polling to be that helpful. There are other relevant factors, beginning with the Iowa electoral landscape as it existed in October, 2007.

Edwards announced his candidacy for President in New Orleans on December 28, 2006, by which time he had been a frequent visitor to Iowa for more than year. He made four trips in 2005 and eleven in 2006 .

By contrast, Obama's first appearance in Iowa was not until September, 2006. Hillary Clinton didn't make her first trip to Iowa until the end of January, 2007.

In 2007, Obama and Clinton stepped up their visits to Iowa. By caucus day in 2008, Edwards had made 47 trips to Iowa compared to Obama's 44,and Clinton's 35.

Had Edwards dropped out after October 10, his early supporters would have had two-and-a-half months to rearrange their thinking, decide on an alternate first-choice candidate and become committed to that candidate. Determining who their second choice would be on January 3 with Edwards still in the race and still their first-choice, may not be an relevant measure.

More significantly, if Edwards dropped out in October, he would not have made his final 11 trips to Iowa. How does one gauge how many supporters he earned as a result of those post mid-October visits? Or who those late supporters have chosen instead of Edwards had he not been in the race?