Democratic Newton Mayor Setti Warren announced Monday that he would jump into the U.S. Senate race against Scott Brown to try to deny the popular Republican a full six-year term in office.
Warren, who's in the second year of his first term as the state's first popularly elected black mayor, is an Iraq War veteran who served a yearlong tour of duty as a naval intelligence specialist.
Warren made the announcement Monday in a largely introductory video posted on a new Senate campaign website.
"As a Democrat, I believe in the core values of creating opportunity for all Americans and protecting our most vulnerable," Warren said in the five-minute video.
The Democrat conceded that while many people don't know him, he is about as familiar to voters as Brown was two years ago.
Warren used the opportunity to criticize the Republican.
"I believe Scott Brown is an honorable man, but he has not been the independent voice in the Senate that so many expected him to be," Warren said.
Warren said Brown has let down Massachusetts voters by supporting the GOP leadership in Congress on issues such as extending the Bush-era tax cuts and opposing an extension of unemployment benefits.
Since taking office, Brown has tried to walk a fine political line as a self-styled moderate Republican, including supporting repealing the federal ban on gays serving openly in the military.
Eric Fehrnstrom, Brown's campaign spokesman, said the senator is focused on his day job.
"It looks like there will be a very crowded Democratic primary, but the election is still 18 months away and Scott Brown's focus in the near term will continue to be on creating jobs and reducing spending," he said.
Democratic Gov. Deval Patrick, who won his own re-election battle last year, had talked up Warren as a possible challenger to Brown even before the mayor had publicly expressed any interest in the race.
Warren also worked in the White House under former President Bill Clinton and is a past staff member for Democratic Sen. John Kerry.
Warren joins a growing Democratic field against Brown, including City Year co-founder Alan Khazei and former lieutenant governor candidate Robert Massie.
Warren and the other challengers to Brown face a number of hurdles. Brown is still popular among voters, according to recent polls, and is sitting on a campaign chest of more than $8 million.
With reporting from The Associated Press and the WBUR Newsroom
This program aired on May 9, 2011. The audio for this program is not available.