The Senate voted Monday to begin a rare, open-ended debate on immigration reform that both parties hope will end with a measure that can win 60 votes and ultimately become law.

“I’m not sure what’s going to happen because it’s been so long since we’ve tried this,” Minority Whip Dick Durbin, D-Ill., said. “But, it really is exciting to think about that men and women elected to this body, known as the greatest deliberative body in America, are finally going to deliberate.”