Unaffiliated Colorado candidate collects signatures after Melat Kiros win in Denver district

An unaffiliated candidate is collecting petition signatures to challenge Democratic nominee Melat Kiros in the November race to represent Colorado’s Denver-centered 1st Congressional District.

The secretary of state’s office on Monday approved Shimon Blau’s petition for circulation. He has until Thursday to submit 1,500 signatures to qualify for the ballot. 

Blau, a doctor, announced his candidacy Sunday in a Facebook post. He said in a video on his Facebook Tuesday that he is a “true independent” who leans left on social issues and right on fiscal issues. 

Republican Christy Peterson is also running for the seat.

Concern for what he views as antisemitic rhetoric from Kiros is what motivated Blau, who is Jewish, to run for Congress, he said in the Facebook post. Maintaining a strong alliance with Israel is a priority of his campaign, as well as healthcare and childcare reform. 

How democratic socialist Melat Kiros stunned Colorado politics with congressional primary win

Kiros was fired from her job as a corporate attorney in late 2023 after she posted an open letter defending students protesting Israel’s war in Gaza from charges of antisemitism. Throughout her campaign, she has been critical of Israel’s military operation in Gaza, which U.N. bodies and human rights groups say amounts to a genocide. She faced criticism for an interview in which she declined to call the June 2025 firebombing attack in Boulder an act of antisemitism.

In the Democratic primary election last week, Kiros, a 29-year-old democratic socialist, defeated U.S. Rep. Diana DeGette, a 15-term incumbent who took office four months before Kiros was born, by more than 20,000 votes. Her upset victory followed progressive wins in New York congressional primaries. 

Blau said he has petition circulators collecting signatures at a few locations around Denver throughout the week as he works to quickly gather 1,500 signatures. He has yet to file a statement of candidacy with the Federal Elections Commission.