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Cori Bush is the latest candidate to ride the progressive wave

On Tuesday, a Black Lives Matter activist ousted a 10-term incumbent congressman in a pivotal Democratic primary election. Cori Bush, a 44-year-old pastor, activist, and nurse beat Missouri Rep. William Lacy Clay in an upset that reflects the increasingly fierce divide between progressive and establishment Democratic candidates. Clay and his father had combined to hold the St. Louis-area seat for half a century.

"It is historic that this year, of all years, we're sending a Black, working-class, single mother, who has been fighting for Black lives since Ferguson, all the way to the halls of Congress," Bush said to a crowd of supporters Tuesday evening, according to USA Today.

"They counted us out," Bush continued. "I’m just the protester, I’m just the activist with no name, no title, and no real money. That’s all they said that I was. But St. Louis showed up today."

Bush ran on a platform supporting the Green New Deal, free college tuition, and defunding the police — stances that prime her to pass the progressive litmus test. She also vowed not to take any campaign donations from political action committees, which comprised the majority of Clay's funding. Bush's views align well with left-wing standard bearers Rep. Alexandria Ocasio-Cortez (D-N.Y.) Sen. Bernie Sanders (I-Vt.), as well as with recent protest demands.

Policy-wise, Clay and Bush were relatively aligned — they both supported Medicare-for-All, and Clay had supported Ocasio-Cortez's Green New Deal proposal — yet they diverged in identity and background. Bush's opponent, Clay, was born into a political family — his father was a civil rights leader who helped to establish the Congressional Black Caucus — while Bush only got into politics after the police killing of Michael Brown in Ferguson, Missouri in 2014.

Bush ran on the message that Clay, who claimed to be devoted to his constituents, spent time in Congress working against the interests of St. Louis voters. And in an easy juxtaposition for the current moment: Just two months prior to the militarization of his city after the uprisings against police violence in 2014, Clay voted against an amendment that would have limited the police department's supply of military-grade weapons. Meanwhile, Bush was leading protests in the city.

Bush won Tuesday night with almost 49% of the vote. She had previously tried to unseat Clay during the 2018 midterms but lost; her run then was documented for the Netflix movie Knock Down the House. Her victory last night reflects a growing impatience among the Democratic base with establishment politicians who are reticent to accept progressive demands around housing, health care, and student debt. Because the St. Louis-area district is majority Democrat, it's almost certain that Bush will sail through the general election in November, and to Washington, D.C., in January 2021.

Bush isn't the only candidate who has successfully carried the progressive torch during this primary season. Jamaal Bowman, a middle school principal in the Bronx who grew up in public housing, beat out the moderate Democratic Rep. Eliot Engel in June. Progressives Ocasio-Cortez and Michigan Rep. Rashida Tlaib additionally held onto their seats amid primary challenges this year.