Gerald Herbert/AP Photo

As the caucuses and primaries pick up pace, with Colorado and Minnesota taking center stage today, many are wondering whether the initial enthusiasm surrounding the Republican race is waning, given the remarkably low turnout in the Nevada caucuses, which came and went with little fanfare.

In Iowa, New Hampshire and South Carolina, turnout surged, compared to four years ago and each state went to a different candidate.

But that trend appears to be on the decline. In both Florida and Nevada, turnout dropped sharply from 2008. Florida saw nearly 280,000 fewer voters in its primary last week, while more than 11,000 fewer voters turned out to vote in Nevada on Saturday compared to four years ago. Mitt Romney won both states by a landslide.

Some observers say the declining interest is a reflection of the lack of enthusiasm for the former Massachusetts governor.

Polls show mixed enthusiasm for the current crop of GOP candidates. More Republican and Republican-leaning registered voters - about 52 percent - said the Republican field is only fair or poor than did so in early January, according to a poll by the Pew Research Center, and only 46 percent had positive opinions of the field. At this time in 2008, 68 percent of Republican and GOP-leaning voters rated the field as excellent or good, according to Pew.

Rep. Ron Paul, R-Texas, the only candidate who doesn't have a win under his belt, also blamed the low turnout on the lack of satisfaction with the candidates in an interview on "This Week" with George Stephanopoulos.

Some observers, however, point to a trend of higher turnout in counties where former House speaker Newt Gingrich outperformed Romney.

"He's much more of an attack dog when it comes to not only his primary opponents but also his potential general election opponent, Obama," said Michael McDonald, a professor at George Mason University who runs the United States Elections Project, which monitors election and turnout data. "The Republican voters really crave someone who's going to display that sort of attack mentality when it comes to the general election. That's something you can get enthused upon. Romney's campaign is not a campaign that seems to be able to spark that kind of enthusiasm."

Turnout is also directly related to how closely voters are engaged in the political process, and that was more the case in early nominating states than in Florida and Nevada.

Interest was boosted in part due to the initial "spectacle" that was created by personal attacks and fiery debate performances, McDonald said. Gingrich's ranking in the polls surged following a debate in which he roasted the national media as well as his opponents. Romney saw a similar boost after the CNN debate in Florida, where the former governor spoke passionately against negative ads targeted against him.

"Certainly, conflict creates an audience. So when candidates are going negative against each other it becomes a spectacle and voters are drawn in to look at the spectacle," McDonald said.

But experts caution that it's too soon to declare Florida and Nevada national bellwethers.

Florida's primary numbers were boosted in 2008 because of a contentious property tax ballot initiative. Voters could also have been deterred from going to the polls by the spate of negative television ads against Gingrich by Romney and his super PAC. And in Nevada, Romney was poised to win because of strong Mormon support and his history in the state. The former Massachusetts won the caucus there four years ago as well.

And in both states, exit polls showed that voters had made up their minds well in advance, unlike in the first three nominating states where a majority decided just days before the election.

In virtually every state, the one attribute voters have said they are looking for is a candidate who can beat President Obama in the general election. That trend could bode well for the Republican nominee, even if enthusiasm in the primaries and caucuses is waning.

The early elections, said Neil Newhouse, the lead pollster for Romney, is more a function of the number of candidates and the type of campaigns they are running rather than an indicator of the general election.

"Those who are trying to make a linkage between the Republican primary and enthusiasm for the fall ticket are just barking up the wrong tree," he said. "What we're seeing is that their [voter's] feeling toward Barack Obama has not changed. The fall election will be about Barack Obama. Once we get through the primary should Romney be the nominee, Republican voter enthusiasm will not be a problem."