By SEJAL GOVINDARAO, Associated Press

PHOENIX (AP) — Adelita Grijalva won the Democratic primary Tuesday for a southern Arizona U.S. House seat long held by her father, the late U.S. Rep. Raúl Grijalva, one of the most senior and progressive power brokers on Capitol Hill.

Adelita Grijalva will face Daniel Butierez, a painting company owner who won the GOP primary, in a Sept. 23 special election for the seat in the heavily Democratic 7th Congressional District.

Raúl Grijalva’s death in March left the seat wide open for the first time in over two decades. Grijalva was a champion of environmental protections and reliably went to bat for immigrants and Native American tribes. He routinely breezed past GOP challengers in the deep-blue district, which stretches across most of the state’s border with Mexico, spanning six counties and parts of Tucson.

Adelita Grijalva dominated the field of Democratic hopefuls seeking the nomination. She said lowering the cost of living, standing up for immigrant rights, and protecting access to Medicaid, Medicare and Social Security are among her top priorities. Grijalva also racked up a lengthy list of heavyweight endorsements — including Democratic U.S. Rep. Alexandria Ocasio-Cortez, independent U.S. Sen. Bernie Sanders and several state and local officials.

“This is a victory not for me, but for our community and the progressive movement my dad started in Southern Arizona more than 50 years ago,” Grijalva said in a statement.

Butierez, who captured more than one third of the vote against Raúl Grijalva last year, also easily clinched his party’s nomination, winning every county by large numbers. He said he’s excited by the results and more optimistic about his chances this go-around because he’s been actively campaigning and he believes he can win over more Democrats in the district.

“The biggest thing is, I’m not running to represent just the Democrats or just the Republicans. I’m running to represent everybody,” he said.

If Adelita Grijalva wins the general election, she would be the first Latina to represent Arizona in Congress.

“In a district that is 60 percent Hispanic, it is critical that voters see themselves in their representatives, and Adelita is the fighter they need in Congress,” said Rep. Linda Sánchez, chair of BOLD PAC, the Hispanic Caucus’ campaign organization.

Grijalva has also pushed back against notions that she’s an establishment candidate and has pointed to her own credentials serving on local governing boards.

She ran against former state lawmaker Daniel Hernandez; digital strategist and reproductive rights advocate Deja Foxx; Indigenous activist and scholar Jose Malvido Jr.; and retired health care executive Patrick Harris Sr. Grijalva led her next closest rival, Foxx, by about 40 percentage points when The Associated Press declared her the winner.

In the GOP primary, Butierez ran against off-road vehicle businessman Jimmy Rodriguez and restaurant owner Jorge Rivas.

The results of Tuesday’s primary will remain unofficial until they are certified on July 31 by the Arizona Secretary of State’s office.

The seat will not decide control of the U.S. House, but it is one of three vacancies in heavily Democratic districts that, when filled in special elections this fall, will likely chip away at Republicans’ slender 220-212 majority in the chamber.

Democrats have a nearly 2-1 ratio registration advantage over Republicans in the 7th District.