Alexandria Ocasio-Cortez’s Democratic primary victory over incumbent Congressman Joe Crowley left many stunned, including members of the Bronx Democratic Party.

Referring to the freshly defeated Crowley, Bronx Borough President Ruben Diaz Jr. told a The New York Times reporter, “We need [Crowley] in Washington, DC. Washington is about consistency and seniority.” Assemblyman Marcos Crespo, the Bronx Democratic Party chairman, told Politico that Ocasio-Cortez’s win “rattled” some members of his party. “I think we don’t have to view it all as a negative,” Crespo said. “There is an energetic new base that identifies as Democrats that are demanding and expecting change.”

Ocasio-Cortez, a Bronx native of Puerto Rican descent, won over 57 percent of the vote to become the Democratic candidate for New York’s 14th Congressional District, which includes parts of Queens and the East Bronx. Ocasio-Cortez ran on a Democratic-Socialist platform that includes universal Medicare, tuition-free college, and abolishing the Immigration Customs and Enforcement agency (ICE).

Ocasio-Cortez, 28, ran a grass-roots campaign, focusing her efforts on door-knocking, canvassing, and using social media to get her message out. Her Twitter has more than 561,000 followers, to Crowley’s 31,000.

In a Twitter post from June 19, Ocasio-Cortez drew attention to Crowley’s absence at a local debate. Crowley instead sent former Bronx Councilwoman Annabel Palma in his place. Using a surrogate to represent him, along with his residence in Virginia, bolstered Ocasio-Cortez’s argument that Crowley was out of touch with his district, which is 51 percent Hispanic.

Yet, Ocasio-Cortez’s win wasn’t simply propelled by Hispanic voters. According to data gathered by the Center for Urban Research at the CUNY Graduate Center, Ocasio-Cortez was the favorite in socioeconomically diverse Queens neighborhoods of Astoria, Sunnyside, and Woodside. In the Bronx, Crowley outperformed Ocasio-Cortez in Country Club, Edgewater Park, and Throgs Neck; Bronx neighborhoods which are also predominantly white and upper-middle class.

Also, in a reversal of home court advantage, Queens-born Crowley did better in the Bronx than in his home borough. In the Bronx, Crowley won 46 percent of the vote, to only 40 percent in Queens, according to the New York State Board of Elections. Ocasio-Cortez performed better in both boroughs within the district.

For some, Ocasio-Cortez’s primary win sets the precedent for the sort of grass-roots campaigning Democrats look to duplicate to unseat the Republican majority this November. Her ability to galvanize enough potential voters to give Crowley his first primary challenge since 2004 made national news. But for the Bronx, her win also underscores the lackluster turnout in the borough’s voting bloc.

Only five percent of active voters in the Bronx’s 14th Congressional District voted in the June 26 primary. In Queens, over eight percent of likely voters went to the polls.

Still, voter turnout in the Bronx for the primary was better than in recent years. In 2016, only four percent of active voters in the Bronx’s 13th Congressional District voted in a primary that ultimately led to the election of the nation’s first Dominican-American congressman, Adriano Espaillat.

In 2016, the Bronx Democratic Party didn’t foresee Espaillat’s primary victory, instead backing former Manhattan assemblyman Keith Wright.