Texas Democratic Rep. Christian Menefee defeated longtime Rep. Al Green in a runoff that was defined by heavy outside spending and clashes over generational change.

The Tuesday result will likely end the long career of Green, a 78-year-old civil rights champion who was running for a 12th term in Washington. He entered the race in the newly drawn Houston-area 18th District after his own district was carved up in redistricting.

Menefee, a 38-year-old Harris County attorney and fellow member of the Congressional Black Caucus, was sworn into Congress earlier this year after winning a special election in January to serve out the remainder of the late Rep. Sylvester Turner’s term. He is expected to cruise to victory in November in the safely Democratic Houston district.