Rep. Chris Van Hollen secured the endorsement of several Montgomery County officials in his campaign for Senate on Monday and dismissed a pair of national liberal groups that are calling for Rep. Donna F. Edwards to enter the race.
Van Hollen, the only candidate so far to declare he is running for the seat long held by Sen. Barbara A. Mikulski, called himself an "effective progressive" in Congress, and said he welcomed a discussion on his record "with anybody who chooses to throw their hat into the ring."
Mikulski announced her retirement last week, and Van Hollen, 56, has moved faster than any other politician in the state to line up support for his campaign. On Monday, the Montgomery County Democrat stood in Rockville with County Executive Isiah "Ike" Leggett and announced endorsements from all nine members of the County Council.
He is also backed by Senate Minority Leader Harry Reid of Nevada.
The seven-term congressman is a reliable vote for Democrats and is close with House Democratic leader Nancy Pelosi. But groups such as Democracy for America — the organization founded by former Vermont Gov. Howard Dean — have likened Edwards to Sen. Elizabeth Warren, the Massachusetts Democrat many progressives hope will run for president in 2016.
DFA and the Progressive Change Campaign Committee have sent emails to members asking them to support Edwards.
Several Democratic sources say Edwards, a five-term congresswoman from Prince George's County, is preparing to run for the seat, but her aides have declined to discuss her plans. A spokesman did not return a phone call Monday.
Maryland's political observers are watching more than a dozen potential candidates closely. Reps. Elijah E. Cummings of Baltimore and John Delaney of Montgomery County as well as C.A. Dutch Ruppersberger and John Sarbanes of Baltimore County have said they are considering the race. So, too, is Baltimore Mayor Stephanie Rawlings-Blake.
Before she gave the annual State of the City address on Monday, Rawlings-Blake told MSNBC that she is taking a "hard look" at the contest.
A growing number of state officials, meanwhile, are throwing their names in for House contests that will come into play.
Del. Kumar P. Barve of Montgomery County said that he will jump into the contest for Van Hollen's 8th Congressional District seat. Barve, a 24-year member of the House of Delegates, is a former majority leader who has been a key ally of House Speaker Michael E. Busch. State Sens. Jamie Raskin and Richard Madaleno and Del. Ana Sol Gutierrez have said they are considering a run.
If Edwards runs for Senate, several Democrats mentioned former Lt. Gov. Anthony G. Brown as a possible candidate for the 4th Congressional District.
Former Prince George's County State's Attorney Glenn F. Ivey considered running against Edwards in 2011 but ultimately dropped out. Ivey did not return a phone call seeking comment.
Baltimore Sun reporters Mike Dresser and Erin Cox contributed to this article.