Rep. Alexandria Ocasio-Cortez told a cheering crowd estimated at over 7,500 at the Whittemore Center at the University of New Hampshire in Durham, New Hampshire Monday night rallying in suport of Sen. Bernie Sanders' 2020 Democratic presidential campaign that the future of the country is in their hands.

"We are at a crossroads in our democracy, a key crossroads," said the New York Democrat, a prominent Sanders surrogate. 

Ocasio-Cortez spoke at the massive get out the vote event after Sunflower Bean played a free concert and other supporters delivered remarks and ahead of Sanders and a performance by the Strokes. The event was packed, with supporters lining the bleachers around the stage. 

In her remarks, Ocasio-Cortez stressed the importance of the movement moving forward as the primary election season goes into overdrive.

"We have to nominate somebody with a political revolution at their back," said Ocasio-Cortez. "It is not going to be any one candidate that defeats Donald Trump—it will be a movement."

The New York Democrat told the crowd that they needed to understand that they are of a movement.

"It's going to take you to do it, mass movement politics to do it," said Ocasio-Cortez. "That's the theory of change, that's what political revolution is all about."

The future of the country needs to be socially advanced and center justice, said Ocasio-Cortez.

"As someone who has been told to 'go back,'" she said, "let me tell you we are going forward."