Rivera was born and raised in Santurce, San Juan, Puerto Rico.[2] He received a B.A. in political science from the University of Puerto Rico in May 1998.[3] Following graduation, Rivera moved to New York to begin a doctoral program in political science at the Graduate Center of the City University of New York.[4] He taught courses at Hunter College until 2002, and served as an Assistant Professor of Political Science at Pace University until his first election in 2010.[4]
After serving as Director of Outreach under United States Senator Kirsten Gillibrand, Rivera decided to run for the New York State Senate in 2010.[7] The incumbent, Senator Pedro Espada Jr., had long been a staple in Bronx politics.[8] Espada was considered the favorite throughout the election.[9] After a hard fought campaign, Rivera ultimately defeated Espada in the Democratic primary.[10] Espada would later be convicted of embezzlement.[11]
In the Senate, Rivera is known as a leading progressive voice.[12] With the Democrats retaking the majority in 2018, Rivera was named Chair of the Senate Health Committee. Rivera has advocated for single-payer health insurance.[13]
