Updated 11:31 a.m. | Former Maryland Lt. Gov. Kathleen Kennedy Townsend won’t run for Senate, and instead is endorsing Rep. Chris Van Hollen’s bid.  

The eldest of former Sen. Robert F. Kennedy’s children had been publicly considering a bid for the open Maryland seat being vacated by Sen. Barbara A. Mikulski. Late last month, she told The Washington Post running for the seat was her “dream,” but said she was “still working on putting things together and making a decision.”  

But Townsend, who lost a 2002 gubernatorial bid and a 1986 congressional race, will endorse Van Hollen in the already heated Democratic primary on Monday afternoon in Silver Spring, Md., according to a release from the congressman’s campaign.  

Kennedy Townsend is on the board of the Democratic opposition research firm American Bridge, but a spokesman for the group said her endorsement did not mean American Bridge would be involved in the race.  

Rep. Donna Edwards, who got in to the race days after Van Hollen, is the other declared candidate. But Democrats anticipate the primary could get more crowded for the rare open Senate seat — only the second in Maryland in the past three decades. Rep. Elijah E. Cummings is considering running, and would be a strong competitor.  

Maryland is a Democratic stronghold, so this primary will most likely choose the next senator.  

Related:

Van Hollen, Edwards Square Off in First Maryland Senate Race Debate


Baltimore Riots Change Senate Race Conversation


Democrats’ Maryland Senate Circus


Van Hollen’s Exit Changes House Democratic Leadership Landscape


Mikulski Legacy Is Beyond Longevity


Roll Call Race Ratings Map: Ratings for Every House and Senate Race in 2016


Get breaking news alerts and more from Roll Call in your inbox or on your iPhone.