Democrat Jillaire McMillan has conceded the close race for House District 19 to Republican Dan Woog, who won by 123 votes.

Woog’s victory, along with Republican wins in two other competitive districts, is expected to break Democrats’ supermajority in the Colorado House.

District 19 is one of three house districts in the state poised to flip from blue to red this election, which would bring the Democratic majority down from 46-19 to 43-22. Democrats would need a two-thirds majority in the House to maintain their supermajority, which allows them to override governor vetoes and put constitutional amendments before voters without Republican support.

As of Friday morning, Woog had 50.1% of the 56,711 votes, while McMillan had 49.9% of the votes. House District 19 encompasses Dacono, Erie, Frederick, Firestone, east Longmont and surrounding areas, and it includes parts of both Boulder and Weld counties.

Because the margin between the candidates is less than 0.5% of the leading candidate’s votes, the race is expected to go to an automatic recount, but the recount is unlikely to affect the results.

The District 19 race has remained tight practically since the first results were posted on election night. The earliest batch of results released at 7:30 p.m. Nov. 5 showed Woog with an eight percentage-point lead over McMillan, but by 9:20 p.m., McMillan had pulled into a four-point lead, with 52% of the vote to Woog’s 48%. And by mid-day on Nov. 6, McMillan still held her lead.

Woog formerly served in the state Legislature as a representative for House District 63. He also previously ran in House District 19 but lost to current Rep. Jennifer Lea Parenti, a Democrat. He said this race had been a long one, but barring an unexpected change, it appears to be over. Woog also said his previous loss in District 19 taught him a lot about the “purple” district.

“I think I just learned a lot from losing … (having) that time to sit back and really listen to the voters and analyze my time as a legislator and see really what people want as a district. I think that gave me a little bit of an advantage this time, to really know and understand that with Boulder County and Weld County, there could be some definite differences in what people are looking for in their legislator,” he said.

McMillan could not immediately be reached for comment, but on her campaign’s Facebook page, she posted a video on Friday congratulating Woog on winning the race.

“This election showed that the voters of HD 19 are split nearly 50-50, and I encourage (Woog) to stay true to his promise to put people over politics and to be a productive and pragmatic leader,” she said in the video.

McMillan thanked her supporters and volunteers, who helped her launch her campaign about three months ago after Parenti said she would not run for reelection. She also said outside groups had spent nearly $500,000 on “offensive personal attacks” during the campaign.

On Thursday night, the Boulder County Clerk’s office posted on X that results for the District 19 race, along with several other contests, will likely be recounted on the week of Dec. 2, after the election results are certified. The post said the county has released its last batch of unofficial election results.

Heading into the Nov. 5 election, Republicans needed to flip three seats in House Democrats’ seismic 46-seat caucus to break their supermajority control of the chamber, which Democrats won — passing the two-thirds threshold — in the blue wave 2022 election.

In addition to Woog flipping District 19, Democratic Rep. Mary Young lost her seat last week in Greeley-based District 50 and Republican challenger Rebecca Keltie appears to have narrowly unseated Democratic Rep. Stephanie Vigil in Colorado Springs’ House District 16, though that race also appears headed for a recount.

Minority Leader Rose Pugliese, a Colorado Springs Republican and the party’s top House official, celebrated the results Thursday night.

“Colorado voters spoke loudly, supporting two common-sense leaders in Dan Woog and Rebecca Keltie,” she said in a statement. “After we saw the people of Colorado defeat Prop HH last year and now three House districts flipping back to Republicans, the message is clear: Coloradans want a lower cost of living and a thriving economy. The Democratic policies pushing higher taxes and fees are not the way forward for Coloradans across the state.”

Democrats still hold the lion’s share of power in the Capitol. Even if they lose three seats in the House, the chamber will still have 43 Democrats to 22 Republicans. In the Senate, Democrats are similarly one seat away from a supermajority: Democrats and Republicans each flipped one seat last week to maintain the 23-12 status quo in the chamber.

“While we will miss our colleagues who worked tirelessly for their constituents, let’s be clear: the priorities of the MAGA-wing of the GOP will be stopped dead in their tracks by voters who elected an overwhelming majority of legislative Democrats, the second largest Democratic majority since the 1960s,” House Speaker Julie McCluskie said in a statement Friday. She added that Republicans’ “self congratulations ring hollow when they are still walking into the Capitol without a shred of voter support for their extreme agenda.”

She said her door “will always be open to members of the minority party to collaborate where we agree.”

The Denver Post contributed to this report.