(CBS News) While an anti-Obama and anti-Democratic wave that swept the nation during the 2010 mid-term elections led Republicans to take control of the House of Representatives, turnout among Republicans appears to be more muted this year.
According to CBS News estimates, 2012 voter turnout is about 6 percent lower compared to the same contests in 2008. On a state-by-state basis, the 9.2 million votes so far in this primary is fewer than the 9.79 million in 2008.
Though some states have seen bumps in turnout from 2008 -- including the first three states of Iowa, New Hampshire and South Carolina -- voting has been down in several subsequent states compared to 2008.
Of course, some special factors could explain lower turnout: In Virginia, only two of the four candidates were on the ballot; Missouri was just a non-binding "beauty contest" primary; And Idaho held caucuses instead of a primary this year. On the flip side, Sen. John McCain had clinched the nomination by the time Mississippi and Alabama voted in 2008, and the longer-than-expected primary season this year likely led to increased voter participation in last Tuesday's contests -- and could lead to increased turnout in the states to come.
Despite the special circumstances, turnout has been down overall.
For example, in Florida's January 31 primary, 1.6 million Republicans voted, compared to 1.9 million in 2008, despite a greater number of registered Republican voters. Another way to put it: 41 percent of voters cast their vote in 2012, compared to 51 percent in the 2008 GOP Florida primary.
Florida Republican Party spokesperson Brian Hughes told Hotsheet prior to the Sunshine State's primary that he anticipated increased participation. "As far as enthusiasm and activity, it seems like we're going to have even higher turnout in the past," he said. But that prediction did not come true.
The story was similar in the Nevada caucuses. The GOP spokesperson predicted high turnout, but the results showed something different: The number of Republican caucus-goers decreased by nearly one-third, with only 32,000 participants.
Of the ten states that held contests on Super Tuesday, turn out was down in most, including Georgia, Tennessee, Oklahoma and Massachusetts.
For instance, in the Georgia primary, 900,000 people voted this year, down 63,000 from 2008.
A theory widely attributed to lower turnout in the Republican primary is an "enthusiasm gap," due to voters not being excited about the candidates, especially as front-runner Mitt Romney struggles to lock down the nomination.
A new poll by Gallup released Thursday reveals that voters are less enthusiastic about the current crop of Republican candidates than they were about their choices in 2008. Although the poll does not connect enthusiasm levels to turnout, this poll makes clear that excitement lacks. One-third of voters polled say they would vote "enthusiastically" for either Mitt Romney or Rick Santorum. It's a similar level of enthusiasm for Romney in 2008, but lower than John McCain in 2008, who obtained the enthusiastic support of 47 percent of those polled.
Republican strategist Steven Lombardo, CEO of StrategyOne and former Romney adviser during his 2008 presidential campaign, said the "enthusiasm gap" is only a "smaller part" of the reason behind lagging voter turnout. He attributed the larger reason is negative campaigning.
Lombardo says the negative tone of the campaigns and the high number of negative ads on television is impacting voter participation. "The negative attacks from all candidates have contributed to a depressed voter turnout," Lombardo said.
"This primary fight has taken some of the energy out," Lombardo added.
On CBS News' "Face the Nation," a week ago, President Obama's campaign adviser Robert Gibbs agrees with the Republican strategist.
"I know at what these candidates have been saying, tearing each other apart with negative ads, it is a process that in many ways has torn each of them down and I think has weakened them for a fall election,"
Democratic pollster Mark Mellman, CEO of the Mellman Group, also largely dismissed the idea of the enthusiasm gap. He said his research shows there is no correlation between voter turnout and enthusiasm. He said people vote because it's their civic duty or because of social pressure, not because of excitement.
Instead, Mellman blames "division in the Republican Party" for low turnout. "There is a relationship between divisiveness and electoral success," Mellman said.
"It's a very bitter and very divisive primary process," Mellman said, adding that "people are dissatisfied with the candidates."
The long-protracted fight has some Republicans worried, including the 2008 Republican nominee, Sen. John McCain.
that "every day between now and November that is devoted to winning the primary is lost on winning the general election. And that, I have to tell you it makes me very worried about our chances of winning in November."
"Bitter divisive primary contests sap the party in November," Mellman said, adding that the long Democratic primary between Hillary Clinton ans Barack Obama in 2008 was different. He said both candidates had high favorability ratings among voters and that their campaign was tough, but not nearly as negative.
"There' really isn't much doubt that [turnout is] down and this has to be worrisome for the Republican Party," Republican strategist Lombardo told Hotsheet.
Lombardo said political campaigns and popular moods ebb and flow, and he said things can shift at the drop of a hat, but he doesn't expect Republican excitement in 2012 come November like the party saw during 2010 midterm elections.
However, another Republican strategist, Whit Ayres, president of North Star Opinion Research, emphatically disagrees. He said the problems plaguing the Republican field and the Republican primary will impact independent voters, but not for long. He predicts they will come around in November when faced with the choice between President Obama and the Republican nominee, regardless of who it is.
"There is such Republican interest in replacing a president they perceive as driving us off a cliff that intensity will be up and turnout will be up," Ayres said.
However, former Democratic spokesman Jim Manley, now a senior director of the Washington, D.C. firm QGA Public Affairs, said Democrats are feeling more optimistic than they were six months ago when the economy was showing no signs of recovery and anticipation over the Republican field was high. He pointed to the improving economy and the prolonged, bitter Republican primary as signs of trouble for the GOP.
"There's a whole heck of a lot of Democrats feeling a lot better these days," he said.