As a political newcomer, Townsend defeated Anthony J. DeLuca—who was then President pro tempore of the Delaware Senate—in the 2012 Democratic primary by 57 percent to 42 percent.[3][4] Townsend went on to defeat Republican Evan Queitsch in the general election, winning 78 percent of the vote.[5][6]
Townsend was reelected in 2014. He defeated primary challenger David L. Tackett with 78 percent of the vote,[7][8] and was unopposed in the general election.[9]
In September 2015, in the wake of Representative John Carney's announcement that he would run for governor of the state, Townsend announced his candidacy for Delaware's at-large seat in the U.S. House of Representatives.[10] On September 13, 2016, his candidacy ended when he placed second in a six-way Democratic primary, behind former state Secretary of Labor Lisa Blunt Rochester (25% to 44%).[11][12]
Townsend supports gun control and has supported a bill in 2018 to ban assault weapons.[13] In 2024, he countered and voted against a bill legalizing medical aid in dying in Delaware.[14][15]