Dan Baer, who served as a diplomat during the Obama administration, said this week that he will enter the Democratic race to challenge Sen. Cory Gardner (R-Colo.) next year, according to Denver television station 9News.

Baer served as U.S. ambassador to the Organization for Security and Co-operation in Europe from 2013 to 2017. He most recently worked as executive director of Colorado’s Department of Higher Education.

ADVERTISEMENT

“I think what most probably voters want to know is that I probably have the same concerns that they do,” Baer, who would be the first openly gay man to serve in the Senate if elected, told 9News. “I mean, I look at what’s going on in our politics today and I want to say: ‘Can somebody please send the manager over? This doesn’t look like the country or the state that I know and that I want to live in.'”

Several other Democrats have already jumped into the race to challenge Gardner, considered one of the most vulnerable Senate Republicans in 2020 and one of only two GOP incumbents up for reelection in the Senate whose state voted for Democratic presidential nominee Hillary Clinton Hillary Diane Rodham ClintonDemocratic groups using Bloomberg money to launch M in Spanish language ads in Florida The Hill's Campaign Report: Presidential polls tighten weeks out from Election Day More than 50 Latino faith leaders endorse Biden MORE in 2016.

John Walsh, former U.S. attorney for the District of Colorado, announced his candidacy on Tuesday, according to the Denver Post.

“Today, one of the biggest challenges we face is our president,” Walsh said in an announcement video. “Our state deserves better than what we’re getting from Donald Trump and Cory Gardner Cory Scott GardnerCook Political Report shifts Colorado Senate race toward Democrat Overnight Health Care: US coronavirus deaths hit 200,000 | Ginsburg's death puts future of ObamaCare at risk | Federal panel delays vote on initial COVID-19 vaccine distribution The Hill's Campaign Report: GOP set to ask SCOTUS to limit mail-in voting MORE.”

The Denver Post editorial board last month retracted its 2014 endorsement of Gardner after he voted against a resolution rebuking President Trump Donald John TrumpBiden on Trump's refusal to commit to peaceful transfer of power: 'What country are we in?' Romney: 'Unthinkable and unacceptable' to not commit to peaceful transition of power Two Louisville police officers shot amid Breonna Taylor grand jury protests MORE’s declaration of a national emergency on the U.S.-Mexico border.

The field of Democrats looking to unseat Gardner includes former state Sen. Mike Johnston and former state House Speaker Andrew Romanoff. Former Gov. John Hickenlooper John HickenlooperCook Political Report shifts Colorado Senate race toward Democrat Willie Nelson playing at virtual fundraiser for Hickenlooper Gardner on court vacancy: Country needs to mourn Ginsburg 'before the politics begin' MORE was considered another likely contender before he opted to launch a White House bid.