Can the Debates Turn Around Romney's Fortunes?

WASHINGTON, Sept. 26, 2012 -- With just one week to go until the first presidential debate, both sides are already deep into spin mode. Both want to set a low bar for their own candidate to be able to clear, while setting expectations sky high for their opponent.

Democrats remind the press that Mitt Romney has had lots of practice with debates this year -- you know, with that whole primary thing.

Republicans counter that President Obama is really smart and very experienced on the national debate stage -- you know, being president and all.

Not surprisingly, the two sides also differ on just how much impact the debate can have on the overall contours of the race. Republicans say they can make a big difference. Democrats say, not so much.

OK, so what does history tell us about the impact of debates on the ultimate outcome of the presidential contest?

After looking through the last 40 plus years of data, Gallup reported back in 2008 that "presidential debates are rarely game changers" and pointed to just a "few instances in which the debates may have had a substantive impact on election outcomes."

Fortunately for Romney, one of those "instances" featured a candidate who was trailing in the polls going into the debates, but came out of the debates -- and the election -- a winner.

That candidate, George W. Bush, did lose the popular vote. And, he did get some help from the Supreme Court. But, the fact remains that Bush came into the debates down 8 points to Al Gore, but came out of the debate period ahead by 4 points.

There was plenty of other activity that took place between Oct. 3 and Election Day that affected the trajectory of that year, but Gallup writes, Gore "might also have won the Electoral College vote had his 8-point pre-debate-period lead not slipped away in the last few weeks of the campaign."

Coming into their first debate on Oct. 3, the Gallup poll showed Gore leading Bush 47-39 percent. Three days after the debate, the race was tied at 43 percent. A poll taken before the second debate on Oct. 11 found that Gore had regained some of his lead (he was ahead 45-40 percent). But, after the second debate, Bush moved into a 2 point lead. The candidates went into the final debate tied at 44 percent. Three days later, Bush was ahead by 4 points.

"Thus, across the entire 2000 debate period, the race shifted from an 8-point lead for Gore to a 4-point lead for Bush," writes Gallup analyst Lydia Saad. "Other campaign factors may have come into play to cause this, but Gallup analysts at the time assigned at least some of the shift to the debates themselves."

So what can 2000 tell us about 2012?