New York's presidential primary will be held Tuesday, and the state's Democrats and Republicans will pick their candidates by choosing delegates.

"They are individuals who are active in the party, and the candidates often recruit them to run as delegates under their banner," says Frank Sorrentino, a political science professor at St. Francis College. "These can be elected officials, they can be party activists or they can be individuals who are just strong supporters of the particular candidate."

Sorrentino says that the delegate process varies from state to state, but in New York, both parties award delegates proportionate to the vote.

In New York, there are 95 delegates at stake on the Republican side, and 291 for the Democrats -- including 44 superdelegates, who are elected officials and party leaders allowed to vote for the candidate of their choosing. 

Superdelegates do not have to follow the popular vote.

Rep. Hakeem Jeffries is one of Brooklyn's superdelegates, but he has also served as a regular delegate in the last two Democratic conventions.

"The convention is an opportunity for people all across the country to rally behind our nominee," Jeffries says. "And begin to come together in advance of the November election."