First-time candidate Trisha Calvarese won the Democratic nomination for Colorado’s special election to replace former Republican U.S. Rep. Ken Buck on Monday in an online convention.

She’ll face Republican nominee Greg Lopez, a former Parker mayor and two-time gubernatorial candidate, in the June 25 election, triggered last month when Buck abruptly resigned from the 4th Congressional District seat he’s held since 2015.

The special election to fill the remainder of Buck’s term — only the second such election in Colorado history — will take place simultaneously with the state’s primary to pick the parties’ nominees for the November election.

“I’ve lived and organized in rural America, and I will be able to hit the ground running, because I know how to navigate Washington, D.C.,” said Calvarese before voting began during the two-hour convention, held on the Zoom teleconference platform.

Calvarese won the nomination with 64.5% of the delegate vote, ahead of mechanical engineer John Padora, who got 35.5% in the third round of voting. Two candidates were eliminated in earlier rounds: Ike McCorkle, a Marine veteran who ran unsuccessfully against Buck in the last two elections, and Karen Breslin, a political science professor who briefly ran for the U.S. Senate two years ago.

A self-described New Deal Democrat, Calvarese was born in Sterling and grew up in Highlands Ranch before launching a career that included political work for the AFL-CIO and the Office of Legislative and Public Affairs at the U.S. National Science Foundation.

Recalling that she returned to Highlands Ranch to provide home hospice care for her parents, who died within days of each other near the end of last year. Calvarese said her late father, a Republican, encouraged her to run for of the seat and was her “very first endorsement.”

“We talked about politics all the time. I loved it. And honestly I really miss it,” Calvarese said. “We would always land on shared values — care, opportunity, time with family. That’s what unites folks in our district. And what they want is someone willing to solve problems, to put people over politics, to lead a new generation of possibilities and to offer a vision of hope over fear.”

Lopez told Colorado Politics he is ready to take his campaign to the voters.

“I’m glad we now know who my Democrat opponent is,” Lopez said in a text message. “As a former governor candidate in 2022, I spent a great deal of time in the 4th Congressional District, and the people of the district know who I am. I have earned their trust in protecting and defending the values of faith, family, and freedom.”

Added Lopez: “I look forward to taking my message and campaign throughout the district once again.”

Lopez and Calvarese have both described the race for the reliably Republican district, which includes all or portions of Douglas and Larimer counties and the Eastern Plains, as pivotal to control of the U.S. House, where the GOP currently hold a 218-213 majority.

“This is a national bellwether, and together we are going to keep the blue wave going,” Calvarese said after she was declared her party’s nominee. “We’re going to defeat Greg Lopez, and we are going to flip this seat — and, with it, the balance of the U.S. House.”

Lopez won the GOP nomination last week at a convention in Hugo, a small town in Lincoln County, after pitching himself as a “placeholder,” willing to keep the seat warm for the remainder of Buck’s term so Republicans can sort out who to nominate for a full term in the primary.

As many as nine Republicans are vying for a spot in the primary, including U.S. Rep. Lauren Boebert, who moved at the beginning of the year from the Western Slope into Buck’s district after he announced he wouldn’t seek reelection.

Other Republicans in the running are state Reps. Mike Lynch of Wellington and Richard Holtorf of Akron, former state Sens. Jerry Sonnenberg of Sterling and Ted Harvey of Highlands Ranch, former radio talker Deborah Flora, business consultant Peter Yu, former top congressional aide Chris Phelen and Hispanic Energy Alliance chairman Floyd Trujillo.

Minutes after Calvarese won the nomination for the special election, Padora released a statement vowing to stay in the race for the primary.

“I plan to show the great people of Congressional District 4 I am the right person to represent them in office,” Padora said. “I am not a career politician. Coming from a blue-collar background and going through an addiction to recovery journey, I know what it’s like to notice our broken systems in this country first-hand, and I believe CD-4 will resonate with my belief in co-governance and my focus on the issues that matter to them.”

Editor’s note: This developing story will be updated.