Updated

Consumer advocate Elizabeth Warren’s likely entry into the U.S. Senate race in Massachusetts could re-energize Tea Party support for Sen. Scott Brown, whose moderation in Washington has deeply disappointed the conservative grassroots movement that swept him to office in early 2010.

“I think she has the capacity to do that,” said Christen Varley, head of the Greater Boston Tea Party, who described Brown’s relationship with the Tea Party as “tense.”

“When you look at the contrast and the ideas and policy agenda that she would bring to Washington, she’s so far off the New England moderate scale, it does run the possibility of re-energizing Tea Party support for Sen. Brown,” she said.

Tea Party activists across the country rallied around Brown in late 2009 to help him win the Senate seat once held by the late Ted Kennedy in a major political upset that halted President Obama’s health care bill in its tracks.

Even though Democrats were able to regroup after losing their supermajority in the Senate and eventually pass the health care bill, Brown continued to enjoy Tea Party support despite his votes for several Democratic jobs bills.

But the honeymoon ended last summer when Brown voted at the last minute for Obama’s financial regulatory legislation, known as Dodd-Frank, prompting many Tea Party activists to cry betrayal. The final straw for others came earlier this year when Brown opposed Rep. Paul Ryan’s 2012 budget plan, which drew praise from conservatives and scorn from liberals for its proposal to privatize Medicare, among other things.

But some Tea Party leaders who said they were considering withholding their support for Brown in 2012 are now having second thoughts after Warren, a hero on the left for her crusade against Wall Street excesses and corporate interests, launched an exploratory committee Thursday.Warren said she plans to make her intentions clear after Labor Day.

“Elizabeth Warren is a game-changer,” Varley said. “Elizabeth Warren is a dyed-in-the-wool progressive. We can say we may not be thrilled with Sen. Brown, but we certainly don’t want Elizabeth Warren.”

Obama tapped the Harvard professor last year to set up the new Consumer Financial Protection Bureau that was authorized by Dodd-Frank. But congressional Republicans lined up against her becoming the bureau's director, and Obama in July chose not to pick her to head the new agency.

That left an opening in Massachusetts where national Democrats desperate to reclaim Kennedy’s seat have been wooing Warren to enter the race. Even though she’s never run for public office, Warren has built a national profile with her battles on behalf of consumers.

Democrats believe she has what it takes to defeat Brown, who is the most popular politician in the Bay State with an approval rating of 73 percent, according to a poll released in March by the Democratic Senate Campaign Committee.

But some Tea Party activists aren’t so sure Warren will rekindle their flame with Brown.

“I think he’s working with a deflated base,” said Matt Clemente, who until last month was the Massachusetts director of FreedomWorks, a conservative group that helps organize the Tea Party movement.

Clemente, who is now pursuing his doctorate degree, said he doesn’t see the base re-inflating to even half of what it was nearly two years ago, when his race against state Attorney General Martha Coakley “had a feel of a national election.”

“There will be less Tea Party support than before,” he said, adding that each member will have to make up their own mind. “Some will get behind him. A lot more will be sitting out.”

“It should be an interesting election,” he added.