WASHINGTON—House Democratic Caucus Chairman Joseph Crowley lost his primary Tuesday night, derailing the career of a top Democrat who was poised to move up the leadership ladder. 

Alexandria Ocasio-Cortez, a 28-year-old and former field organizer for Sen. Bernie Sanders’ presidential campaign, led Crowley 58 percent to 42 percent, with 88 percent of precincts reporting, when The Associated Press called the race.

The longtime New York lawmaker was the first sitting Democrat to lose a primary this election cycle.

Ocasio-Cortez criticized the incumbent as tied to special interests and a political machine that dominated local politics in the district, which includes parts of Queens and the Bronx.

Crowley’s loss is sure to send shockwaves through the House Democratic Caucus. He had been mentioned as a potential candidate for speaker if Democrats win back the House and Minority Leader Nancy Pelosi chooses not to run or has trouble garnering enough votes.

Ocasio-Cortez said Crowley’s sway in the caucus would come up occasionally on the campaign trail.

“The thing that we always say is, ‘Power is good if you’re using it for the right things,’” she said. “What is this power doing for us? It’s not doing anything.”

His defeat could set off a battle for his leadership position, should he step down. Former GOP Leader Eric Cantor announced the day after he lost his Republican primary to Dave Brat in 2014 that he would step down from his post.

California Rep. Linda T. Sanchez may have a fight on her hands if she wants to move up the ladder. She narrowly won her bid for caucus vice chairwoman.

Crowley was first elected to represent the 14th District in 1998. He had not faced a primary challenge in 14 years.

Ocasio-Cortez said in a phone interview last week that her campaign had caught fire in the final weeks leading up to the primary. She was backed by national liberal groups including MoveOn and Democracy for America.

She was originally contacted by the group Brand New Congress to run against Democratic Rep. Jose Serrano, but ultimately decided to challenge Crowley, since she lives in the 14th District. A video detailing her story caught some attention, in which she pointed out that their representation did not reflect the majority-minority district. Forty-nine percent of the district is Latino, 9 percent is black, 16 percent Asian-American, and 22 percent of the population is white.

Ocasio-Cortez has taken liberal positions including backing Medicare-for-All legislation and abolishing Immigration and Customs Enforcement.

She said the focus was on field organizing and also benefited from supporters across the country phone banking and writing postcards to voters in the district, which includes Queens and part of the Bronx. She said her campaign had five core staffers and a couple hundred volunteers.

Ocasio-Cortez described her strategy as “to excite and turn out our base that has not felt excited about their representation in a very long time.”

“I think that for so long people in New York City have accepted corruption and legal corruption as a fact of life. And this year everybody is just sick of it,” she said last week. “There are some places where we need to go red to blue. And there are some places that we need to go blue to bluer.”

Ocasio-Cortez is expected to be in a strong position to win the district in November. Inside Elections with Nathan L. Gonzales rates the race Solidly Democratic.

Pelosi doesn't see party shift to left in Crowley defeat

WASHINGTON (AP) — House Minority Leader Nancy Pelosi says while the New York City district of a defeated Democratic congressman may have shifted to the left, that doesn't necessarily mean it's happening everywhere.

The California Democrat spoke to reporters Wednesday, hours after the surprise primary defeat of Rep. Joe Crowley. He's a 10-term lawmaker who's been part of the party's House leadership.

Pelosi says, "Nobody's district is representative of somebody else's district." She says the outcome is "just a sign of vitality of our party."

Pelosi says she doesn't think Crowley's defeat will encourage other Democrats to challenge her for her leadership job after the November elections. She says she's always challenged.

Crowley lost to 28-year-old Alexandria Ocasio-Cortez, a political newcomer who worked on the 2016 presidential campaign of Vermont Sen. Bernie Sanders.