Mitt Romney is the Republican front-runner in national polls and he has raised the most money, but he is lagging in support with an important Republican constituency, especially in the key early states: Tea Party activists. Tea Party leaders say Romney is not the leading candidate among their constituents, even in New Hampshire, which is considered a must-win for the former governor of neighboring Massachusetts. “I wouldn’t say Romney’s the favorite,” says Jane Aitken, coordinator for the New Hampshire Tea Party coalition. Aitken declined to say who is in the lead, as her group does not endorse candidates and even their member groups that do endorse have not yet decided who to support. But she says that from conversations with other Tea Party leaders, there is no clear favorite. 

“The front-runner [among the Iowa Tea Party] would be Michele Bachmann,” says Ryan Rhodes, chairman of the Iowa Tea Party. It is a particularly bad sign for Romney that the qualities in Bachmann that Rhodes cites approvingly are precisely the inverse of Romney’s weaknesses, which are his past apostasies and countless policy reversals. “She’s been consistent. She’s not going to apologize every two seconds for doing things that are not in line with the Tea Party. She hasn’t waited to hear what some poll said.”

In polls Romney sometimes under-performs his overall numbers among self-identified Tea Party supporters. For instance, a McClatchy-Marist poll found Romney in the lead among all Republican-leaning voters but Rick Perry leading among Tea Party voters.

In the 2008 cycle Romney assiduously courted conservatives, calling for doubling the size of the prison at Guantánamo Bay and flip-flopping on gay rights, abortion rights and immigration reform (he now opposes all of them). His adoption of doctrinaire conservatism on social issues continues in this campaign. On Tuesday his campaign announced a Justice Advisory Committee, which will be co-chaired by Judge Robert Bork, the infamous extremist whose Supreme Court nomination was rejected by the Senate.

But some grassroots conservative activists think Romney has been tacking back to the center in this cycle. “He moved to the right in 2008, now he’s going to the left,” says Rhodes. Certainly, Romney has been campaigning as a front-runner, focusing on the more broadly appealing subject of jobs while staying out of the debt-ceiling debacle until a deal had been reached.

Tea Party activists also complain of lackluster outreach from the Romney campaign. “I wouldn’t say Romney has been doing very well with Tea Party conservatives,” says Rhodes. “He’s barely been talking to us.”

“He basically sticks with state Republican party events,” says Aitken. As Politico’s Ben Smith reported Monday, Romney has generally had a more spare schedule than other candidates.

The other problem for Romney is his past moderation and the fact that he seems to let his saner instincts prevail on any subject where he hasn’t yet calibrated a suitably conservative response. Romney upset many conservative—most notably Rush Limbaugh who said “Bye-bye nomination”—when Romney admitted in June that anthropogenic climate change is occurring. At the first GOP debate Romney disagreed with Tea Party phenomenon Herman Cain’s opposition to letting Muslims serve in the cabinet.

Then there’s the elephant in the room for Romney: that he signed into law a healthcare reform bill in Massachusetts that relied on an individual mandate which President Obama used as a model for the Affordable Care Act. “I think [Romney’s problems among Tea Partyers] is principally because of the mandate in Massachusetts,” says Phil Kerpen, vice-president for policy at Americans for Prosperity, a fiscally conservative organization that works with Tea Party groups. “The mandate has become a major issue for conservatives since federal healthcare reform.”

What was once Romney’s signature achievement, and a reason cited by National Review for endorsing him in the last presidential cycle, has become an enormous liability. The policy, of course, is no more liberal than it was in 2007, but conservatives afflicted with Obama Derangement Syndrome now consider it incipient Bolshevism. Romney’s solution—decrying the ACA as a “power grab” while defending his law because it was only at the state level—has strained credulity and failed to mollify his right-wing critics.

FreedomWorks, the Tea Party–affiliated conservative organization run by former House Majority Leader Dick Armey, is opposed to Romney’s candidacy. Although FreedomWorks employees point to his overall record and perceived phoniness, their main policy objection is his record on healthcare.

It seems as if economic conservatism has actually replaced religious social conservatism as the doctrine requiring pure, deeply felt and 100 percent faithful adherence. In Massachusetts the state Citizens for Life group is launching a ballot campaign to repeal Romney’s healthcare reform, even as they say Romney’s record on abortion itself is acceptable.

Some Tea Party leaders say Romney still stands a chance with their constituents. Sal Russo, the veteran GOP operative who founded Tea Party Express, says his group polls its donors weekly on their preference in the presidential race. No single candidate has emerged as the consistent winner, and no one has broken 30 percent. “The healthcare mess in Massachusetts raises a red flag,” says Russo. “We met with Romney and shortly thereafter he started to address it. I worked for Ronald Reagan for years, and many times people didn’t agree with Reagan on issues. Whatever somebody did in their college term paper or public office in the past, that’s the past. The question is what’s your plan today? We’re a lot more forward-looking than backward-looking.”

So can a more aggressive campaign of outreach win over Romney’s Tea Party skeptics? “If he has to answer tough questions about his global warming stance and Romneycare, it’s not going to be easy for him,” says Rhodes. But no one ever said running for president is easy.