Bush’s primary win essentially guarantees her a seat in Congress representing the heavily Democratic St. Louis area. Missouri’s 1st Congressional District has been represented by Clay or his father for a half-century. Bill Clay served 32 years before retiring in 2000. William Lacy Clay, 64, was elected that year.

Clay didn’t face a serious challenger until Bush.

In a stunning upset, Black Lives Matter activist Cori Bush has defeated 10-term incumbent Rep. Lacy Clay in the Democratic primary for Missouri’s 1st Congressional District, according to the Associated Press. Bush, a minister and registered nurse, has been heavily involved in protests against police violence since the 2014 Ferguson protests