A Democratic Socialist who upset Rep. Joe Crowley (D-N.Y.) in a primary on Tuesday night had previously said that Israel had committed a “massacre” in the Gaza Strip.

Alexandria Ocasio-Cortez, 28, who soundly defeated Crowley as part of a party primary for New York’s 14th congressional district, which covers parts of Queens and the Bronx, is a member of the Democratic Socialists of America, which supports the BDS movement.

In a May 14 tweet, Ocasio-Cortez said Israel’s killing of Palestinians along the Gaza border was a “massacre,” and that “no state or entity is absolved of mass shootings of protesters.”

“There is no justification. Palestinian people deserve basic human dignity, as anyone else,” she said. “Democrats can’t be silent about this anymore.”

Some 60 Palestinians were killed in “March of Return” protests orchestrated by the Palestinian terror group Hamas on May 14, which is also the secular date of Israel’s Independence Day. Hamas leaders later said that at least 50 of those killed were members of the terror group.

The primary victory of Ocasio-Cortez over Crowley—the No. 4 Democrat in the House of Representatives, who many viewed as vying for a top leadership position in the next year—may represent a broader shift in the Democratic Party towards the more progressive wing championed by Vermont Sen. Bernie Sanders, who is also a Socialist and has strongly condemned Israel’s actions in recent months.

In a statement, the Jewish Democratic Council of America, while congratulating Ocasio-Cortez on her victory, said it disagreed with her stance on Israel.

“We disagree with her past statement regarding Israel, as well as her affiliation with the Democratic Socialists of America, which supports the boycott, divestment and sanctions [BDS] movement targeting Israel. In the coming days and months, we hope to learn more about Ms. Ocasio-Cortez’s views, but at the moment, her position on Israel is not in line with our values.”