Former Colorado Gov. John Hickenlooper declared an early victory Tuesday night against former Colorado House Speaker Andrew Romanoff in the Democratic primary race for Senate.

Hickenlooper had received dozens of endorsements over the past few weeks from progressive and moderate allies around the nation, ranging from U.S. Sen. Elizabeth Warren to La Plata County Commissioner Clyde Church.

“Let me be clear, change is coming, and you and I are going to bring it together,” Hickenlooper said in a campaign video. “I’ve never lost an election in this state, and I don’t intend to lose this one.”

Polling locations closed at 7 p.m. in Colorado on a night shaping up to have the biggest primary turnout in state history.

In Southwest Colorado, Hickenlooper took the lead early when he was reported to win 53% of the primary vote in Dolores County. He also won both San Juan County and Archuleta County with about 70% of the vote. At 8:30 p.m., Hickenlooper carried La Plata County by 67% and Montezuma County by 63% of the vote.

In a video acknowledging his loss, Romanoff pledged his support for Hickenlooper, saying, “This is obviously not the outcome we were hoping for.”

“I’ve learned this week there are far more important things than losing an election,” Romanoff, whose father recently passed away, said in a Zoom call with supporters. “I’ve made it very clear when we started this race ... that I would support the Democratic nominee.”

The two candidates are vying to challenge Sen. Cory Gardner, the one-term Republican incumbent who first vaulted to the Senate in 2014. Gardner campaigned heavily first for U.S. representative in 2010 and later for the Senate seat held by Mark Udall on issues such as health care and the economy. He won a tight race for the Senate by less than two percentage points.

Now, as political winds shift, Gardner is considered one of the most vulnerable Republicans in the Senate. He is one of only two Republican senators up for re-election in a state won by Hillary Clinton in the 2016 presidential election, along with Sen. Susan Collins in Maine.

Gardner has walked a tightrope this election as he balances his support for President Donald Trump with the political realities of a state unsupportive of the president. Trump held a campaign rally with Gardner in Colorado Springs on Feb. 20, but Gardner has since distanced himself from the administration and its more hardline positions, including quietly withdrawing his support for repealing the Affordable Care Act from his campaign website.

Tuesday’s primary sets the stage for an election with voting taking up an unusual proportion of the spotlight. Mail-in ballots have become a campaign sticking point, as the country attempts to hold elections during a pandemic. Colorado became a state with universal mail-in ballots in 2014 and has enjoyed consistently high voter turnout since.

Final tallies are expected later, as additional ballots are counted.

Jacob Wallace is an intern for The Durango Herald and The Journal in Cortez and a student at American University in Washington, D.C.