Fiery consumer advocate Elizabeth Warren beats Scott Brown in Massachusetts Senate race

By Martin Finucane, Stephanie Ebbert and Mark Arsenault, Globe Staff

Democrat Elizabeth Warren defeats Harvard Law professor Scott Brown. (Thea Breite/Globe Staff)

Democrat Elizabeth Warren, the Harvard Law professor who promised to battle for a struggling middle class, defeated incumbent Republican Scott Brown tonight in the Massachusetts Senate race, despite Brown’s attempts to paint himself as a one of a dying breed, a moderate New England Republican.

Elizabeth Warren spoke to a voter over the phone from her campaign office in IBEW Local 103 in Dorchester this morning (Aram Boghosian for The Boston Globe)

The victory by Warren, who made history as the first woman elected to serve as a US senator from Massachusetts, marked a comeback by the state’s Democrats after Brown’s bruising 2010 upset win in a special election to fill the seat left vacant by liberal lion Edward M. Kennedy.

In a hard-fought race that drew national attention, the two candidates had crisscrossed the state, aired tough TV ads, and tangled in three heated debates, while spending some $70 million between them.

In other races, President Barack Obama, on his way to victory nationally, beat Mitt Romney handily in traditionally blue Massachusetts, even though Romney is a former Bay State governor and planned to hold his election night party here.

Voters in the Fourth Congressional District returned a member of the storied Kennedy political family to office, electing Democrat Joseph P. Kennedy III over Republican Sean Bielat, while Richard Tisei failed in his bid to become the lone Republican in the state’s congressional delegation, losing the Sixth District race to incumbent Democratic Representative John F. Tierney. Voters also approved Question 1, a “right to repair” law, and Question 3 , authorizing the use of medical marijuana.

Speaking to jubilant supporters at the Fairmont Copley Plaza hotel, Warren said, “For every family that has been chipped and squeezed and hammered, we’re going to fight for a level playing field and we’re going to put people back to work.”

“To everyone who shared your hopes and dreams ... I will never forget. I will always carry your stories with me in my heart. I won’t just be your senator, I will be your champion,” she said.

Flanked by his wife and two daughters, a smiling and relaxed Brown thanked cheering supporters at the Boston Park Plaza Hotel, saying Warren had won it “fair and square.”

“I just want to thank you for the opportunity and whatever the future holds, I am a fortunate man to be where I’ve been,” he said.

Warren had delivered a ringing message, portraying herself as someone who would advocate for ordinary people who were being cheated by a system rigged for the wealthy. She charged that Republicans were on the side of “billionaires and millionaires and big oil companies.”

In debates, she sought to turn attention to Brown’s voting record. A high school debate champion, she relentlessly highlighted his votes against jobs bills, against equal pay for women, and against mandated insurance coverage for birth control. She also criticized his joining other Republicans in a no-taxes pledge. She said that a vote for Brown was a vote for Republican control of Congress.

US Senator Scott Brown got into his trademark pickup truck after voting in Wrentham today (Gretchen Ertl/AP)

Warren, an Oklahoma native, stumbled in her initial response to revelations that she had claimed Native American heritage. She had identified herself as a minority in a legal directory for nearly a decade, and she was listed as a Native American in federal forms filed by Harvard and the University of Pennsylvania where she worked. But she insisted her heritage claim played no role in her career advancement.

Brown attacked her for it in the first two debates, but he relented in the third.

In a state known for its liberal leanings, Brown had sought to maneuver to the middle. While trumpeting his anti-tax stance, he highlighted a Congressional Quarterly study that determined he was the second-most bipartisan member of the Senate. Some of his ads included images of President Obama; others did not mention he was a Republican.

He promised to be an “independent voice” who would work with both sides in an increasingly polarized Washington.

Cultivating the image of a folksy everyman, he wore a barn jacket and drove a pickup truck.

In his remarks tonight to supporters, he quipped that the “most difficult part” about losing was “I now have to break the news to my truck that I’ll be taking it home.”

Brown shot to political stardom after his surprise victory over Democratic Attorney General Martha Coakley, with some even mentioning the former male model in the early euphoria as presidential timber. He was seen as a crucial vote in the Senate to block Obama’s health care reform plans.

But political observers had warned that a large turnout driven by interest in the presidential election could hurt his chances of winning a full term as senator.

Warren entered the race in September 2011 and was instantly anointed as the Democratic frontrunner. A first-time candidate, she was known for her criticism of the financial industry, which she has accused of carrying out predatory practices. Her work in Washington included setting up a new consumer protection agency.

Many precincts reported long lines and steady turnout this morning as voters turned out despite temperatures that had dropped near freezing overnight. Secretary of State William F. Galvin predicted that as many as 3.2 million people could vote by the 8 p.m. poll closing time, surpassing the turnout record set in 2008.

“I can’t stand that woman,” Brown voter Marie Cahalane said of Warren at the polling place at Temple William Shalom and Charlotte Bloomberg Jewish Community Center in Medford. “She’s angry and belligerent. She just has an edge to her that I don’t think is conciliatory.”

She went on to say that she saw Brown as someone who could help bring divided politicians to the middle.

Gretchen Brown said she supported Warren. “I just always vote for the woman,” she said. “I really think it’s important to have as many Democrats as possible in the Senate because of the general issues of the economy.”

Added her husband, Robert Brown: “I want to keep the Senate Democratic. I’m really concerned about Republicans. I don’t think there’s any substance to their positions, just a lot of rhetoric.”

Voters also cast ballots for a third referendum, Question 2, an assisted suicide proposal, which appeared unlikely to pass early Tuesday. And voters had their say on races for other congressional seats, Governor’s Council, state Legislature, various regional and local offices, and local referendums.

Frank Phillips, Michael Levenson, Noah Bierman, Matt Carroll, Maria Sacchetti, Brian Ballou, Peter Schworm, and John R. Ellement of the Globe staff as well as correspondents Evan Allen, Johanna Kaiser, Melissa M. Werthmann, Sarah N. Mattero, Patrick D. Rosso, and Jessica Bartlett, contributed to this report.