A Washington-based group that backs pro-choice Democratic women candidates has formally endorsed state Sen. Katherine Clark's bid for Congress, opening up the possibility of a sizable independent expenditure in the race.
The organization, EMILY's List, put Clark "on the list" months ago, giving her access to a nationwide network of 2 million donors encouraged to give money directly to her campaign.
But the formal endorsement means EMILY's List's political action committee could spend separately on door knocking and literature promoting Clark's candidacy.
A spokeswoman for the group declined to outline its plans. But in a statement, EMILY's List president Stephanie Schriock said Clark "has an impressive record fighting for women and families in her community."
Clark welcomed the endorsement.
"I'm committed to standing up to the extremist Republicans who are trying to turn back the clock on women's rights when they should be working to help our families and communities by securing pay equity, increasing the minimum wage, investing in early education and reducing gun violence, and I'm grateful to have EMILY's List's support in my campaign to bring these priorities to Washington," she said, in a statement.
Clark, of Melrose, is one of two Democratic women in the race to fill the seat vacated by former U.S. Rep. Edward Markey, who won election to the U.S. Senate in June.
State Sen. Karen Spilka, of Ashland, is also vying to represent the district, which bends through the suburbs north and west of Boston.
After EMILY's List put Clark "on the list," the Spilka campaign pushed for similar treatment, but to no avail.
Clark has racked up a series of endorsements from women's groups and individual leaders, while Spilka has carved out a niche as the labor candidate.
The major Democratic hopefuls signed a "People's Pledge" last month designed to limit outside spending in the race.
The agreement states that if an outside group advertises on television, radio or online on behalf of a candidate, that candidate must make a donation equivalent to half the expenditure to the One Fund Boston, set up to benefit the victims of the Boston Marathon bombings.
The agreement does not prohibit independent expenditures on door-knocking or mailers.
The other Democrats in the race include state Sen. Will Brownsberger of Belmont, Middlesex Sheriff Peter Koutoujian of Waltham, state Rep. Carl Sciortino of Medford, Arlington author Martin Long and Stoneham resident Paul John Maisano, who works in the construction industry.
The candidate who wins the Democratic nomination is expected to claim the seat in a deep-blue district. Three Republicans are also in the running.
This program aired on September 20, 2013. The audio for this program is not available.