Sen. Patty Murray (D-Wash.), the chairwoman of the Democratic Senatorial Campaign Committee, extended an enthusiastic endorsement from the committee to Rep. Shelley Berkley (D-Nev.) Thursday, but stopped short of doing the same for Democratic candidates in New Mexico and Connecticut.

Of Berkley's entry into the Nevada race, Murray said, "Shelley rises to the top in her energy and her knowledge of the state and her enthusiasm and we're very proud to support her."

Murray also noted the quick backing Berkley won Thursday from Senate Majority Leader Harry Reid (D-Nev.).

While Murray praised Reps. Martin Heinrich (D-N.M.) and Chris Murphy (D-Conn.) in their open-seat Senate races, she said the committee has not yet extended any official backing to either one.

Murphy already has a primary opponent in Connecticut, secretary of State Susan Bysiewicz, and Heinrich is likely to face a Democratic primary as well.

"I didn't say I wasn't going to endorse Heinrich," Murray said. "We are here in April and it's three months into the cycle and we are looking at all these states and determining where they are individually."

The difference, said Murray, is that while Nevada is seen as a prime pick-up opportunity, New Mexico's seat is currently held by a Democrat and there are "a number of people who are looking at that race."

Murray also stressed that she doesn't see an endorsement from the DSCC as a hindrance to candidates.

"I don't have the NRSC's problem," Murray said, referring to a slew of Tea Party-backed challengers who battled establishment GOP candidates last cycle — a pattern she  expects to repeat itself next year. "I don't have bloody primaries in half of our races."