Senate Minority Leader Harry Reid is endorsing Democratic Congressman Chris Van Hollen for the seat being vacated by Maryland's longtime Democratic incumbent Sen. Barbara Mikulski.  

Reid's backing for Van Hollen Friday comes even as other Democrats weigh a run for Mikulski's seat. They include Reps. Elijah Cummings and Donna Edwards, a favorite of progressives.  

Van Hollen is the only declared Democratic candidate so far, and his pragmatic profile and prominent role in House leadership give him early advantages.  

The early endorsement from Reid, just days after Mikulski announced her retirement and Van Hollen declared his candidacy, could help cement Van Hollen as the front-runner for the Democratic primary.