Club 20 said the show will go on at its traditional political forum Sept. 19, even if the Democrats and half the Republicans don't show up.
The Democratic nominee for U.S. Senate, former Gov. John Hickenlooper, and the party nominee in the 3rd Congressional District, Diane Mitsch Bush, previously said they would not attend.
On Tuesday evening, the Republican nominee in the House race also pulled out. Rifle restaurant owner Lauren Boebert had defeated incumbent U.S. Rep. Scott Tipton in a GOP primary upset.
That leaves U.S. Sen. Cory Gardner of Yuma, the incumbent Republican, to enjoy the platform for all of western and much of southern Colorado on a statewide program produced by Colorado Mesa University and livestreamed statewide for free on Facebook and YouTube.
Club 20 said it had already adjusted the format to feature Boebert in the absence of the Democrat, when the Republican nominee asked to send a prerecorded video answering submitted questions.
"Lauren immediately said yes to the Club 20 debate, Diane Mitsch Bush said no," said her campaign spokeswoman, Laura Carno, Thursday evening. "There can be no debate with only one person. We were looking for a way to address the Club 20 members on issues important to them. We didn't come to an agreement on that with Club 20. Lauren is moving on to a very busy in-person campaign schedule."
Boebert also sought and submitted a video last week at the Colorado Water Congress, when Mitsch Bush participated live. Hickenlooper also submitted a prerecorded video to the statewide conference of water managers and interests.
Club 20 declined the Boebert campaign's request. Bobert's campaign did not immediately respond to a request for a comment.
“It appears that campaigns do not want to be accountable to voters, are trying to limit public exposure, and don’t want to answer questions that are not scripted in advance,” Christian Reece, the business and civic coalitions executive director, said in a statement.
“Club 20 will not compromise the format or integrity of our debates for any candidate, Republican or Democrat. Club 20 forces candidates to answer hard questions in a transparent manner to help the voters of Western Colorado better educate themselves. Every candidate for political office should be able to answer policy questions and demonstrate to the public their stances on the critical issues impacting our region.”
This story was updated Thursday morning to include a comment from the Boebert campaign.