A millennial candidate has shaken up the US Democratic Party by defeating the incumbent congressman for his seat.
The out-of-nowhere upset of Crowley, the fourth-ranking Democrat in the House, in Tuesday's New York primary stunned the Democratic establishment, shook up the party's line of succession to become the next House speaker and might even be an early sign of a mounting progressive insurgency – potentially with major ramifications in 2020.
Crowley, a 10-term Democrat, had been tipped as a future party leader or even Speaker of the House.
Ocasio-Cortez, a former Bernie Sanders volunteer from a Puerto Rican family, won with 57.5 percent of the vote.
Crowley had not faced a challenger from his own party in 14 years in the mostly ethnic minority district, which covers parts of the Bronx and Queens.
Ocasio-Cortez will now face Republican candidate Anthony Pappas in the November mid-terms.