Former Massachusetts governor Mitt Romney is generally regarded by Republicans as their most likely standard-bearer against President Obama in 2012.

LAS VEGAS, NV - OCTOBER 18: Former Massachusetts Gov. Mitt Romney participates in the Republican presidential debate airing on CNN, October 18, 2011 in Las Vegas, Nevada. (Photo by Ethan Miller/Getty Images)

And yet, Romney’s frontrunner status belies the fact that real doubts remain within the GOP primary electorate about him.

Nowhere are those lingering questions more starkly on display than in a new Washington Post-Pew Research Center poll that asked respondents to pick a single word to describe each of the leading Republican candidates for president.

Among all respondents — Republicans, Democrats and independents — 60 people said “Mormon” when asked for a one-word description of Romney while 17 said “health care”, 13 said “good” and 13 said “flip-flop”.

The findings grow even more interesting — and indicative of Romney’s potential perception problem — when only Republicans and Republican leaning independents are included.

Among that smaller group, “Mormon” still leads the way — with 26 mentions — followed by “health care/Romneycare” at 11 mentions and “politician” at 8 mentions.

While none of those three words are overtly negative — and the Post-Pew pollsters didn’t attempt to categorize what respondents meant to convey with the word they chose — they also all represent already-known trouble spots for Romney.

His faith has not come under heavy scrutiny in this campaign but when Romney ran in 2008 there was evidence that his Mormon faith was viewed skeptically by evangelical voters.

Given the disdain with which Republicans view President Obama’s health care plan and the connections Romney’s opponents have sought to make between it and the plan he signed in Massachusetts, it’s tough to see how lots of mentions of “Romneycare” are a good sign for his candidacy.

Ditto the “politician” mentions. Not an ideal descriptor in an election cycle that has been defined so far by voters’ distaste for politics as usual.

Romney’s perception problem is made even clearer when his top three one-word responses among Republicans are compared to those of Texas Gov. Rick Perry and businessman Herman Cain.

First, Perry. “Texas” led the way with 32 mentions followed by “conservative” at 10 and “no” at 9.

“No” is quite clearly not good for Perry — where else can you get that kind of high-end political analysis! — but both “Texas” and “conservative” are either neutral or positive by our reckoning.

(Worth noting: Negative words outnumbered positive ones offered about Perry at a rate of two to one. That was roughly equivalent to Romney’s ratio of negative to positive.)

Cain’s top three? “Businessman” placed first with 25 mentions followed by “9-9-9” with 24 mentions. “Good” and “interesting” each were mentioned 17 times by Republicans and Republican-leaning independents. It’s hard to argue that all four of those terms are anything but positive for Cain.

As with any poll, it’s important to note that this survey is a snapshot in time. Still, Romney and his team would be foolish to totally dismiss the results.

Voters often make up their minds not based on a detailed examination of each candidates’ policy positions or on which candidate they think gives their side the best chance of winning but rather on their impression (right or wrong) about each person running.

The one-word responses suggest that Romney still has work to do when it comes to how GOP voters perceive him. Good thing for him that he has the money and time to address those image issues.