The Senate Democratic campaign arm is backing Rep. Jacky Rosen's newly announced bid for Senate in Nevada, even as a fellow Democratic lawmaker continues to weigh a bid.

The Democratic Senatorial Campaign Committee (DSCC) announced its decision to back Rosen on Thursday afternoon, hours after she announced her Senate campaign.

"Jacky is a tireless, trusted problem-solver and a champion for Nevada’s middle class families — we are proud to endorse her campaign," Sen. Chris Van Hollen (D-Md.), the committee's chairman, said in a statement.

"We look forward to doing all we can to support her campaign.”

ADVERTISEMENT

The immediate endorsement by DSCC stands out since Rep. Dina Titus (D), who has been in Congress since 2009, is still openly mulling a Senate bid.

Rosen, a freshman lawmaker who won a tight bid for her House seat in November, told The Nevada Independent that former Senate Democratic Leader Harry Reid Harry Mason ReidSenate Republicans signal openness to working with Biden Mellman: The likely voter sham Bottom line MORE — the dean of the Nevada Democratic Party — had encouraged her to run.

Reid's endorsement played a significant role in the DSCC's decision to back Rosen, a source told The Hill. Reid's allies began to circle the wagons around Rosen in the hours since she announced her bid Thursday morning.

Nevada freshman Sen. Catherine Cortez Masto, Reid's pick to fill his seat when he announced his retirement after 2016, endorsed Rosen on Thursday, as did freshman Rep. Ruben Kihuen, another Nevada Democrat who won an endorsement from Reid during his bid for Congress.

"I can't control what Sen. Reid does nor what Jacky Rosen does nor what Dean Heller Dean Arthur HellerOn The Trail: Democrats plan to hammer Trump on Social Security, Medicare Lobbying World Democrats spend big to put Senate in play MORE does," Titus said Wednesday, according to the Las Vegas Sun.

"I can only control what Dina Titus does. So I will make my decision based on that — not on Sen. Reid's preferences, whatever they may be, and for whatever reason they are."

Titus also noted in the interview that she took down Reid's preferred candidate when she was forced to run in another area after redistricting in 2012.

Rosen announced her bid Thursday, blasting Republican Sen. Dean Heller as an "enabler" of President Trump and signaling she'd make opposition to Trump a key piece of her campaign.

"Now more than ever, Nevadans deserve a Senator they can trust to be an independent voice standing up to President Trump, not his enabler," Rosen said in a statement alongside her announcement.

"Senator Heller might not sound like President Trump, but his voting record shows he supported Trump’s agenda 100% of the time in his first 100 days."

Updated: 5:30 p.m.