U.S. Rep. Ed Perlmutter on Thursday formally endorsed state Sen. Brittany Pettersen as his successor, calling the Lakewood Democrat “a tough campaigner and a thoughtful public servant who can hit the ground running in Congress.”

Perlmutter, the Arvada Democrat who has represented Colorado’s 7th Congressional District since 2007, announced on Jan. 10 that he wouldn’t seek a ninth term this year.

“Brittany understands the struggles facing so many Coloradans right now and will fight for our community in Washington,” Perlmutter said in a statement. “She will continue to work to help Coloradans and businesses recover from the pandemic and build a brighter future for our children, grandchildren and her young son, Davis. She has my support and I will do everything I can to help her win.”

Perlmutter’s endorsement arrives days after two potential primary challengers, Jefferson County Commissioner Lesley Dahlkemper and state Rep. Brianna Titone, announced they wouldn’t jump in the primary, clearing a path for Pettersen to secure the Democratic nomination. Titone endorsed Pettersen.

In a statement, Pettersen thanked Perlmutter, pledging to carry on his fight for the district’s constituents.

“Ed has been a mentor and friend to countless Coloradans,” she said. “His leadership embodies his love of people, our state and our country. Like Ed, I promise to get up every single day and fight for the hardworking people of Colorado’s 7th Congressional District and make sure they always have a voice in Washington.”

Pettersen’s campaign said Perlmutter’s nod is the 100th formal endorsement her campaign has received since she declared her candidacy on Jan 11.

Pettersen, who was first elected to the legislature in 2012, said last week that she raised more than $150,000 in the first five days of her campaign. She started the race with roughly $45,000 left over from a brief 2017 run for the congressional seat while Perlmutter was running for governor.

First-time candidates Kyle Faust and Julius Mopper have filed to seek the Democratic nomination in the district.

Four Republicans are running for the seat: first-time candidate Erik Aadland, a West Point graduate and former oil and gas executive; Laurel Imer, a former legislative candidate and strong supporter of ex-President Donald Trump; economist Tim Reichert, the president and CEO of a Denver-based valuation firm; and Teller County resident Carl E. Anderson. Other Republicans are exploring bids, including state Rep. Colin Larson, R-Littleton.

National Republicans said last year that they were targeting Perlmutter and have stepped up interest in the district since he announced his retirement.

The 7th CD’s boundaries were redrawn last year by the state’s independent redistricting commission, moving the Democratic-leaning district closer to a toss-up. Its new boundaries cover Broomfield, Jefferson County and six mountain counties stretching south past Cañon City in central Colorado.

Colorado’s primary election is June 28.