Sen. Patty Murray (Wash.), the No. 4 Democratic Senate leader, is endorsing Sen. Hillary Rodham Clinton (N.Y.) for president, the latest in a string of prominent female lawmakers to back Clinton’s candidacy.

Murray is the Democratic Conference secretary, the highest elected female in the party’s Senate hierarchy. Her backing of Clinton comes on the heels of Sen. Edward Kennedy’s (Mass.) endorsement earlier this week of Sen. Barack Obama (Ill.), a move that many viewed as a major boon for Obama and a blow to Clinton’s campaign.

Both Obama and Clinton have been heavily courting their fellow Senators for support as the two battle it out for their party’s nomination. The race for the Democratic nomination is now a head-to-head contest, with former Sen. John Edwards (N.C.) set to announce his withdrawal at 1 p.m. today.

Washington state Democrats are holding their presidential nominating caucus on Feb. 9. Both Murray and Sen. Maria Cantwell (D-Wash.) have now endorsed Clinton.

Of other Democrats in the state delegation who have endorsed in the presidential race, Rep. Jay Inslee is with Clinton and Rep. Adam Smith is supporting Obama.

— Erin P. Billings