Illinois lieutenant governor Juliana Stratton won the Democratic primary race to succeed Illinois’ US senator Dick Durbin in Washington, beating out US representative Raja Krishnamoorthi.

Stratton, a progressive with the support of governor JB Pritzker, had been behind Krishnamoorthi in polling until recent weeks, when an infusion of cash from Pritzker and hardening sentiment on immigration pushed aside the relatively moderate congressman. Stratton also faced competition on her left from congresswoman Robin Kelly, which threatened to split the progressive vote.

Republicans have not won a statewide election in Illinois in more than a decade; the winner of the Democratic primary is expected to win the general election in November. Stratton, who will face former Republican state party chair Don Tracy in November, would be the 15th Black US senator in American history.

With Chicago still recovering from the upscaled ICE raids and concomitant street protests of Operation Midway Blitz, immigration policy separated the two front-runners. Stratton called directly for the abolishment of ICE, while Krishnamoorthi has been more nuanced, calling for the abolishment of “Trump’s ICE” in a fusillade of late-game ads across the state.

Krishnamoorthi raised more than $30m for this Senate run, second only to US senator Jon Ossoff of Georgia this cycle. The five-term congressman has been criticized for raising money from Trump supporters, people aligned with India’s nationalist movement and an executive at AI company Palantir, with critics saying the representative’s political allegiances are compromising, according to the Chicago Tribune.

A Pac that’s supporting Krishnamoorthi, the Indian American Impact Fund, ran ads boosting Kelly, seen as a way to blunt Stratton, Politico reported. Kelly, the third major contender, served the second congressional district since 2013. Both Stratton and Kelly are Black with deep ties to the state’s Black community. Former Chicago mayor Lori Lightfoot supported Kelly, as did the Congressional Black Caucus.

Stratton was aided by Pritzker’s donations to Illinois Future Pac, which is running pro-Stratton ads. She has served under Pritzker since 2019.