Who won the VP debate? Why the polls were so different

Republican vice presidential nominee Rep. Paul Ryan, of Wisconsin, right, and Vice President Joe Biden discuss a point during the vice presidential debate at Centre College, Thursday, Oct. 11, 2012, in Danville, Ky.

/ David Goldman

Shortly after last night's spirited vice presidential debate, CBS News and CNN released instant poll results providing some insight into who voters thought won the evening's showdown - Vice President Joe Biden or Wisconsin Rep. Paul Ryan. Both polls were conducted shortly after the end of the debate, but they told two very different stories.

According to the CBS poll, Biden delivered a decisive victory, with 50 percent of respondents electing him as the winner and 31 choosing Ryan.

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CNN's poll, however, showed a much closer contest -- with Ryan leading by four points, at 48 percent to Biden's 44 percent.

So what accounts for the difference?

"The CNN and CBS News post-debate polls were conducted among two different samples of voters so different results are not that surprising," said Jen De Pinto, manager of surveys for CBS News' polling unit. "The CBS News Poll interviewed uncommitted voters who watched the debate -voters who are undecided in this election or pick a candidate but say they could change their minds."

Uncommitted voters represent about 15 to 20 percent of the electorate and are potentially up for grabs, according to De Pinto, as most do not align themselves with a political party. In fact, more than half identify as independents.

The CNN survey, meanwhile, conducted interviews with a sample of 381 registered voters nationwide who watched the debate, not just those who are undecided or could change their minds. That sample represents a broader portrait of the electorate and includes many voters who have already decided on a candidate.

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According to Sarah Dutton, CBS News' director of surveys, polling the views of uncommitted voters can be suggestive of which candidate might gain support as a result of the debate.

"As the fall campaign continues, the two candidates are vying for an ever-shrinking sliver of the electorate - uncommitted or persuadable voters," said Dutton. "We are especially interested in the reactions of these voters to the debates -- because their support for a candidate could tilt the outcome of the election."

CBS News has been conducting post-debate instant reaction polls among uncommitted voters since 2004.

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[jbm30022]

Okay, CBS is a purveyor of balanced reporting, right?
So where in this did they report how long CNN has been conducting polls? Must be important as they reported their own experience in conducting polls.
Maybe not so insignificant Mr. Holmes.

[pafaye]

Ok - Potential explanation of the differences between CBS and CNN poll returns now understood, but.......considering the power that supposedly sophisticated poll results can have on the electorate; why could not this have been explained at the same time the poll results were released. I watched a number of post debate shows and commentators seemed not to have an explanation as to the disparity. If we are going to compare poll results side by side, certainly significant differences such as now explained, should not surface days after the debate. Apples and Oranges!

[axhandlebill]

The only thing here that is dying as some put it, is the real Americans that should be voting, instead they are all dead, from all wars of America.
How many grandfathers, father, sons and brothers and sisters must we lose before we all start acting like real Americans and be more responsible in our actions and deeds?????

[red_dot]

Partisan democrats are dying of thirst, and they saw a mirage in Biden's boorish performance.

[GOP-R--Con-Men]

Ryan drank gallons of water and you say Democrats are thirsty?

[NotAGolfer]

GET REAL, "journalist" Lucy Madison. You know the answer. The reason the CBS poll shows Biden ahead is right there in the FINE PRINT:

"Of those polled, "58 percent call themselves independents, 17 percent identify as Republicans, and 25 percent say they are Democrats."

This ratio of Dem:Rep is drastically higher than any polling agency puts the national ratio of likely or registered voters. You have a really bad sample. And don't try to argue that that many more Democrats are undecided than Republicans. No poll comes close to backing that up either. This was a bad poll. Whether on purpose or accident, only your news organization knows.

[talkvent]

Would this be the same home of that noted new guy Dan Rather and his made up news?

[talkvent]

let me guess CBS called the inner city?

[Closeted_Moderate]

Or maybe they called the inbred hillbillies and hicks who self ID as Republicans.

[jeffs55]

The current "coach" has an almost four year losing record. In the college world who would still have their job? Fire the coach.

[Talldrinktongie]

Agreed. Can a fiscally responsible CEO run his business into unfathomable deficit and keep asking for more credit (read: taxes) and keep his job? I think not. It's simple arithmetics: You cannot spend more than you make!

[Closeted_Moderate]

Please name me exactly how ANY past president or mitt Romney or Palin/McCain could have dug us out of this deep of a whole any faster.

You folks are so dishonest or amnesiac, because a simple Google search would show tons of articles from early 2009, where every reputable economist was saying in 2009 after the crash that it would take a minimum of 5-7 years to get back to 6% UE rate, NO MATTER WHAT WAS DONE. That was the best case scenario in 2009. There were just far too many jobs lost in 18 month to magically bring back within four years.

[vpcharan]

It should be obvious for any one with a real brain made of grey matter. The problem is nearly half of the Americans have a brain with fibrotic tissue, not the real grey matter. Since people with fibrotic brain are incapable to distinguish facts from fiction, it is obvious why the polls of the VP debate incongruent.

[hypnotoad72]

People have to be told this sort of thing?