Manny Rutinel, a progressive state representative, defeated a moderate Democrat to win the primary election in Colorado’s most competitive swing district, according to The Associated Press.

Now he will face Representative Gabe Evans, a Republican seen as vulnerable, in a race that will help determine which party controls the House.

A Dominican American former animal rights activist and lawyer with a significant social media following and a knack for fund-raising, Mr. Rutinel appealed to voters with his multicultural biography in a suburban area north of Denver that is nearly 40 percent Latino.

Late Tuesday, he was leading by more than 25 percentage points over Shannon Bird, a white moderate who had argued that she had broader appeal in the general election. In a statement, Ms. Bird congratulated Mr. Rutinel and urged voters to unite against Mr. Evans.

The district, one of Colorado’s ranching and agricultural hubs, narrowly voted for Joseph R. Biden Jr. in 2020 and for President Trump in 2024. It is one of just a handful of battleground House districts with a substantial Latino population. Mr. Evans, the incumbent, is Mexican American.

Even before winning the Democratic nomination, Mr. Rutinel had become a frequent target of Republican attacks, a potential preview of the costly and bruising general election campaign that is expected to come. The House G.O.P. campaign arm has highlighted his long history of criticizing the consumption of meat and dairy products as a way to cast him as unfit to represent the agricultural district.

Mr. Rutinel has since backtracked on some of his positions, telling The Colorado Sun that “like all industry, there are bad apples, and I’ve spoken out against those bad apples that cause extreme and unnecessary animal cruelty in parts of the food industry and against the environmental cost of unsustainable food practices.”

Mr. Rutinel moved to Colorado in 2020 to work on Senator John Hickenlooper’s first Senate campaign.

The race will also test the district’s views on artificial intelligence and the power of the technology industry to influence voter sentiment.

Mr. Rutinel, who helped write Colorado’s law regulating artificial intelligence, had been aided by millions of dollars from outside groups with ties to tech leaders who are worried about unchecked A.I. Many of the same groups spent heavily against Ms. Bird, who campaigned against aggressive A.I. regulation.

One super PAC in favor of A.I. regulation ran ads supporting Mr. Rutinel that featured Pope Leo XIV saying that “artificial intelligence needs to be disarmed.” The Colorado Catholic Church made clear that it does not endorse any political candidate.

Mr. Evans has been vocal about his concerns about overregulating A.I.