WASHINGTON (Reuters) - Former Wisconsin Senator Russ Feingold endorsed Elizabeth Warren's bid for a Senate seat on Tuesday, a strong sign that the prominent consumer activist's Massachusetts campaign will be a top priority for liberal Democrats in 2012.
Warren, a Harvard Law School professor and Wall Street critic, is running for the Senate seat now held by Republican Scott Brown, the upset 2010 winner of a special election to succeed the late Senator Edward Kennedy, a Democrat who had held the seat for more than 45 years.
Republicans are eager to hold Brown's seat, and Democrats see it as perhaps their best chance to pick up a seat as they struggle to hold onto their six-seat Senate majority in November 2012.
The influential Feingold announced that Warren would be the first U.S. Senate candidate endorsed by Progressives United, his political action committee, and sent an email asking for donations for her.
Warren, who helped create President Barack Obama's Consumer Financial Protection Bureau, entered the Senate race with a message of fighting for the middle class. She faces a primary election in September 2012 for the right to compete against Brown in the general election.
Brown, who campaigned as an everyman who drives a pickup truck, has been popular with voters since his election and staked out mostly moderate positions in Congress.
Early polling showed the two locked in a close race. Warren led Brown by 46 percent to 44 percent in a survey taken September 16 to 18 by Public Policy Polling. The survey involved 791 Massachusetts voters and had a margin of error of plus or minus 3.5 percent, suggesting Warren and Brown are in a dead heat.
(Reporting by Patricia Zengerle, additional reporting by Ros Krasny in Boston, editing by Cynthia Osterman)