Rep. Alexandria Ocasio-Cortez (D-NY) injected much-needed energy into a Democratic National Convention that risked dragging on Monday night, telling the Democratic faithful about her own journey from waiting tables and helping her mother fend off foreclosure after her father died from cancer.

“I’m here tonight because America before us has a rare and precious opportunity in Kamala Harris,” she said. “We have a chance to elect a president who is for the middle class because she is from the middle class.”

Ocasio-Cortez took the stage just moments after Harris—the party’s presidential nominee—made a surprise appearance on stage, walking out to Beyoncé’s hit song “Freedom” and a standing ovation from a packed crowd at the United Center in Chicago.

Harris’ appearance—and AOC’s speech soon after—provided a shot in the arm just as the event crawled into its fourth hour of programming.

Ocasio-Cortez, who rose from a perpetual thorn in the side of congressional Democratic leaders to become a uniter and a leader in recent years, plied the party faithful with talking points about saving freedom, raising the minimum wage, lowering prescription drug prices, abortion rights and corporate greed.

But she also briefly addressed an issue that divides the party: Israel’s relentless war against Hamas terrorists in Gaza, which has killed tens of thousands of innocent Palestinians. She praised Harris’ work in addressing the war, which has divided Americans bitterly over the role of U.S. aid to Israel.

“She is working tirelessly to secure a ceasefire in Gaza and bring the hostages home,” she said.

She also tore into Donald Trump, painting the GOP presidential nominee as a leader who would “sell this country for $1 if it meant lining his own pockets and greasing the palms of his Wall Street friends.”

Ocasio-Cortez also called him a “two-bit union buster who thinks of himself as more of a patriot than the woman who fights every single day to lift working people out from under the boots that tread on our way of life.”