The disconnect between the polls that show Mitt Romney and Barack Obama in a dead heat and the media conventional wisdom desperately pronouncing Obama the easy victor is being turned on its head in the Massachusetts Senate race. There, it is Republican Scott Brown that seems to be running the better campaign, yet the polls are starting to show a consistent lead by his challenger, Elizabeth Warren.

Though Brown’s approval rating is no longer the stratospheric 73 percent it was only last year according to a Democratic committee poll, he is still above water at 55 percent among registered voters and 57 percent among likely voters. A new poll shows Massachusetts voters think Brown is running the more positive campaign, 35 percent to 21 for Warren. And Brown’s strong ties to the state are not lost on voters, nor is Warren’s lack of same; only 13 percent of voters think she has a strong connection to the state. Brown’s approval rating among independents is 67 percent and 30 percent among Democrats. So what’s causing Brown’s poll slide?

Alex Burns thinks it’s the natural outgrowth of running as a Republican in a deep blue state: “It’s a state so strongly Democratic that the 2010 GOP wave had little impact there, and where Brown’s 14-point lead among independents in the WBUR still leaves him trailing by 5 points overall,” he writes. That’s true: the MassLive.com report on Brown’s approval notes that he gets 92 percent support from his own party, but that only represents about one in every ten Massachusetts voters.

There’s another possibility, however, and it’s one that should concern the Brown campaign. Warren is this campaign season’s original class warrior. It was her pro-government rant that laid the ground work for Obama’s “you didn’t build that” speech, and she is only running for the Senate because the GOP blocked Democrats’ original plan for her: as the head of a new consumer watchdog bureaucracy. And true to form, her current advertising campaign attacks Brown for sticking up for private industry and business owners while Brown ties Warren to Occupy Wall Street.

But that may play right into Warren’s hands. The Boston Globe reports that Warren’s populism may be working:

In the survey, 39 percent of likely voters believed Warren “will stand up for regular people when in the Senate,” an improvement from 30 percent from a poll in February.

On the same question, Brown’s support dropped to 29 percent from 33 percent.

In what the station described as a sign that Warren’s campaign themes seem to be resonating with voters, the poll found that 35 percent of voters view Warren as the candidate who best “understands the needs of middle-class families.” Only 27 percent said that phrase described Brown.

That “regular people” question showed a 13-point swing. The fallout from Romney’s fundraiser remarks may be overstated by the media, but if the GOP gets successfully tagged as the party for the rich, Brown will be put in the uncomfortable position of having to either distance himself from his party’s presidential ticket or struggle to fight Warren’s class warfare. Brown probably never expected to be in this situation; he’s the pickup-driving local guy and Warren is the tenured Harvard professor from out of state. In almost every way, Brown is running the superior campaign. But if Warren has the right message, that might be all the overwhelmingly liberal electorate there is looking for.