Will independents really decide the election?

Much is made every presidential election year of the independent vote as candidates attempt to appeal to this voting bloc that doesn't identify with either Republican or Democratic ideals - or, perhaps, with a little bit from each. They might be fiscally conservative and socially liberal or they might want to exhibit their independence. Regardless, they are increasing in size and significance.

In the swing states, the number of independent or unaffiliated voters has risen since 2008. For instance, in Florida, the number of unaffiliated voters in 2008 was 2.1 million; this year it's 2.5 million - more than Republican and Democratic voter registration combined. North Carolina was home to 1.4 million unaffiliated voters in 2008 and 1.7 million now. Republicans there saw no gain in voter registration in the past four years and the Democrats only 100,000. Nevada boasts 40,000 more non-partisan voters this year while the Republicans lost 9,000 voters and the Democrats gained only 10,000. In Colorado, unaffiliated voters surpassed registered Republicans and Democrats. (Ohio, Virginia and Wisconsin do not ask voters for party affiliation.)

The evidence behind the growing number of independents is abundant. A recent Pew Research poll from August shows a similar trend. Based on interviews with 13,000 registered voters across the country, one-third of respondents indentified as independents - an increase from 27 percent in 2004. Although personal identification does not equate to official voter registration status, the findings are clear: a large number of Americans are shifting away from political parties.

The trend has been on the upswing for decades. A separate Pew Research study from 2009 looks at party affiliation of all Americans based on Gallup surveys. It shows that only 15 percent of Americans identified as independent in 1945. The number gradually increased until its height in 2009, with 36 percent identifying as independents.

"What we found over the years is that party identification certainly shifts with events, but the most notable trend is the growing number who... reject partisan labels," said Michael Dimock, associate director of research at Pew. Dimock said the party association tends to decline as the public becomes disenchanted with the political process and political institutions and become frustrated with partisan politics - factors that don't help the incumbent.

Tired of eight years of a Republican presidency, independent voters shifted toward Democrat Barack Obama in 2008, who espoused a politics focused, as he famously said, not on blue states or red states but on the United States. It was a campaign theme that spoke to independent voters, who helped propel him to victory in 2008, winning 52 percent of independents to John McCain's 44 percent.

Recent polls, however, show that Mr. Obama will have a difficult time replicating those numbers this time. The latest Quinnipiac/CBS News/New York Times poll shows that Mitt Romney is leading among independent likely voters in Virginia by a striking 21 points. He is also leading among independents in Ohio by six points and 5 points in Florida.

Both Romney's and Mr. Obama's campaigns are separately touting their advantage in early voting in key battleground states. There are so many ways to spin the numbers it's difficult to determine who actually has the advantage. But it is just as difficult for the campaigns to know who the unaffiliated voters cast their ballots for. A Romney aide conceded that they look at polls to determine how independents are voting. With 18 percent of early voters in Florida not associated with the major political parties and 40 percent in Iowa not affiliated, it's a number that the campaigns have to worry about.

"It's not a good predictor for how people vote," CBS News' polling director Anthony Salvanto cautioned about registered independents, indicating that it's difficult to tell which party they back.