Del. Heather Mizeur, left, chats with Lt. Gov. Anthony Brown during an event in Crisfield, Md., in July. Both are candidates for Maryland governor. (AP Photo/Patrick Semansky)

Del. Heather R. Mizeur has picked up an endorsement in Maryland’s gubernatorial race from Progressive Neighbors, a group based in Montgomery County that is led by liberal activists.

In a statement, Progressive Neighbors called Mizeur (D-Montgomery) “the most progressive candidate in the race.”

“An accomplished legislator, able to reach across the aisle and bring ideological opponents together in pursuit of common interests, Delegate Mizeur will also be Maryland’s first female governor as well as possibly becoming America’s first openly gay governor,” the organization said.

Both Mizeur and Attorney General Douglas F. Gansler (D), a former Montgomery County state’s attorney, competed for the endorsement of the group, which was founded in 2006.

A third candidate for the Democratic nomination next year, Lt. Gov. Anthony G. Brown (D), did not participate in the endorsement process, which included a 20-question survey on issues such as alternatives to incarceration, public financing of campaigns, decriminalization of marijuana and transgender rights.

Gov. Martin O’Malley (D) won the endorsement of Progressive Neighbors in the 2006 Democratic primary. He was the mayor of Baltimore at the time.