One of the state's most influential coalitions of local labor unions will endorse Rep. Chris Van Hollen's campaign for Senate on Thursday, despite a deep history of supporting his primary opponent, Rep. Donna F. Edwards.
Seven local SEIU unions, representing more than 40,000 members in Maryland -- including hospital workers, teachers and security guards -- will throw their weight behind Van Hollen, the Montgomery County Democrat running for retiring Sen. Barbara A. Mikulski's seat.
The endorsement is significant in part because SEIU is known for its organizing prowess on behalf of Democratic candidates, providing a deep well of volunteers and advertising money. But it is also noteworthy because the unions have long been associated with Edwards, and were a major player in her 2008 primary campaign that toppled incumbent Rep. Albert R. Wynn.
Van Hollen "has a record of standing with labor and workers," said Ricarra Jones, with 1199 SEIU. "We're going to go with a person who is going to best represent our interests in the Senate."
In 2008, SEIU officials touted their support for Edwards as a "message" to establishment Democrats. The union funneled more than $1 million toward her campaign, blanketing airwaves with anti-Wynn ads in the weeks before the primary.
The group has subsequently been involved in several statewide campaigns, including the 2012 same-sex marriage referendum fight, as well as the successful effort to raise the state's minimum wage.
Edwards has aggressively courted labor, and has called attention to several trade agreements Van Hollen has supported over union objections.
But several officials said 1199 SEIU members felt betrayed by the Prince George's County lawmaker's support for a new, non-unionized hospital that is being proposed near White Oak in Montgomery County, even as the nearby Laurel Regional Hospital is being closed.
Another powerful state union, the Maryland AFL-CIO, has said it will not endorse in the Democratic primary.
The announcement is also a blow to Edwards because she needs outside groups, including labor unions, to help close a 10-to-1 disadvantage in fundraising. Both candidates have received some labor nods -- Edwards, for instance is backed by IBEW Local 26 -- but none of the unions that have endorsed so far have the pull of SEIU.
"When you are in the middle of a battle about Maryland's progressive values, there is no one you want on your side more than SEIU," Van Hollen said in a statement. "Together, we will continue to work to grow our economy and extend the ladder of opportunity to everyone in our state and across the country."
A Baltimore Sun-University of Baltimore poll last month showed Van Hollen with a 14-point lead over Edwards among likely Democratic primary voters. Nearly a quarter of those surveyed had not yet made up their mind, or were backing someone else.
But the landscape could change after another influential group announced this week it will spend $1 million in advertising on Edwards in the Baltimore region. Washington-based Emily's List, which helped elect Mikulski in 1986, backs Democratic women candidates who support abortion rights.
Edwards also announced endorsements Wednesday of three members of the Congressional Black Caucus: Democratic Reps. Lacy Clay of Missouri, Robin Kelly of Illinois and Hank Johnson of Georgia.
"While Maryland has lost more than 72,000 manufacturing jobs since NAFTA, Congressman Van Hollen's been in Congress standing with Republicans and green lighting nine free trade agreements," Edwards spokesman Benjamin Gerdes said in a statement. "That's not a labor record that puts Maryland families first."