Romney boosters have always argued that should he become the nominee, the desire to defeat Obama will be the only motivation the GOP base needs to become active, whatever its lingering doubts about Romney's conservatism.
But this year's caucuses not only confirm that many conservatives are still reluctant to embrace Romney, they suggest that the party regulars aren't very energized.
Yes, Romney did win a state that he lost during his 2008 presidential run, beating Rick Santorum by eight votes. But Romney lost to the former Pennsylvania senator among groups that form the traditional activist base of the GOP: registered Republicans, conservatives, supporters of the Tea Party movement, and evangelical Christians.
And among voters who considered being a "true conservative" the most important candidate quality, Romney only garnered 1 percent of the vote.
And it isn't clear that Romney's problems with these groups would disappear were he the nominee. I spoke to a number of supporters of other candidates who said they weren't sure that they could vote for Romney -- even in a general election against Obama.
"I don't trust Mitt Romney's conservatism," Santorum supporter Karen Heinlein, of Stanhope, told me. "I would really have to think about it if the Republican nominee was Mitt Romney whether I would go and vote for him or if I would stay home."
Even if Romney skeptics were to hold their noses and vote for him, the question remains whether they'd be willing to go the next step of donating their time and money to get him elected.
Though one might argue that there's little one can tell from a single night of voting in one state, four years ago, the energy on the Democratic side was already obvious by this time.
The top Democrats filled large ballrooms and small areas during their campaign stops through the Hawkeye State -- and their supporters were frothing at the mouth for victory after two terms of President Bush. In his victory speech, Obama spoke to thousands of cheering fans.
By contrast, most Republican events this year were subdued affairs. Though media may have reported "packed rooms" at campaign events before the caucuses, the venues were quite small.
And there wasn't the type of chanting, sign waving and electricity that existed among Democrats in 2008 when a whopping 239,000 turned out for their caucuses.
This year, Republican turnout was just 122,255. Though that was up almost 4,000 votes from four years ago, it isn't very impressive for several reasons.
One, the number of registered Republicans rose by more than 38,000 during the intervening time period. Two, there wasn't a contested race on the Democratic side, meaning more independents voted in the GOP caucuses this year and that turnout among registered Republicans actually fell.
And three, more Republicans were actively competing in the caucuses this time, which should have driven up turnout if voters were excited about the choices.
In the end, Romney's vote total was virtually identical to what he received in 2008 -- actually, the 30,015 he received was a decline of six votes.
Though Romney arrived in New Hampshire on Wednesday in good position to win the Republican nomination, Republicans should be worried that the conservative voter enthusiasm that drove massive GOP gains in 2010 may not be there for them this November.
Philip Klein is senior editorial writer for The Examiner. He can be reached at firstname.lastname@example.org.