Another Democrat is running for the chance to take on U.S. Sen. Cory Gardner, the Colorado Republican ranked among the most vulnerable Senate incumbents in the 2020 election.

Medical recruiter Danielle Kombo, who ran unsuccessfully for a Douglas County state House seat last year, on Tuesday jumped into the crowded primary vowing she won’t seek a second term unless she helps implement universal health care.

“By the end of my term in the Senate, every Coloradan will have access to affordable health care or I will not seek a second term,” Kombo said at a campaign launch event in Lone Tree.

“Career politicians don’t make commitments to deliver like that, but we can’t keep sending career politicians to the Senate and expect them to vote for us over their own careers.”

She joins former state Sen. Mike Johnston and former state House Speaker Andrew Romanoff in a Democratic primary field that also includes scientist Trish Zornio, activists Lorena Garcia and James Blanton, and pharmacist Dustin John Leitzel.

Gardner is one of just two GOP senators seeking re-election next year in states won by Democrat Hillary Clinton – she carried Colorado by five points – and his race is listed as a toss-up in an initial rating by Roll Call magazine.

Kombo, 38, lost a bid to unseat House Republican Leader Patrick Neville by 25 percentage points. It was her first run for office.

She supports aggressive action on climate change, including the United States rejoining the Paris Climate Agreement, and backs the DREAM Act, which would provide a path to citizenship for immigrants brought to the country illegally when they were children.

Kombo’s campaign manager, Barrett Rothe, who made an unsuccessful run for another Douglas County House seat last year, said the campaign plans to set up a procedure through its website allowing voters to schedule phone calls with the candidate. She’s also recruiting members to serve on advisory committees devoted to a number of broad policy areas.

According to the most recent campaign finance filings, Gardner’s campaign had $1.7 million on hand at the end of 2018.

The race for his seat, which could determine which party holds the majority in the Senate, is expected to be the most expensive in Colorado history.