The Iowa presidential caucuses begin on Monday evening, bringing the Democratic Party one step closer to determining who its presidential nominee will be this November. Based on how many of the 2,100 precinct delegates he or she win tonight, each candidate will eventually lay claim at the state party convention to his or her share of the 41 national convention delegates up for grabs (plus an additional eight unpledged superdelegates).

That isn’t much, considering that the candidate will need 1,991 national delegates total to win the nomination. But whoever wins tonight’s caucuses will have the political momentum necessary to remain competitive.