He was the Republican Party nominee in the 2016 U.S. Senate election in Connecticut, losing to incumbent Democrat Richard Blumenthal.

[citation needed] After graduation from college, Carter was commissioned as an officer in the United States Air Force through ROTC.

[citation needed] Carter's active military duty ended in 1999, after which he pursued a career in healthcare.

[6] In 2013,[7] and again in 2015,[8] Carter also introduced legislation that addressed firearm access for people diagnosed with mental illness and determined to be at risk of harming themselves or others.

"[10] Carter supports "No-Fly, No-Buy" legislation, as long it includes checks and balances for gun buyers wrongly placed on terrorist watch lists.

[11] On April 4, 2016, Representative Carter announced his intention to seek the U.S. Senate seat held by Democrat Richard Blumenthal.

[12][13] He was being challenged for the nomination by Jack Orchulli, CEO and co-founder of a Michael Kors apparel company and nominee for the U.S. Senate for this seat in 2004 and by August Wolf, investment executive and former Olympic athlete.

[14] Connecticut Republican Party rules state any candidate receiving 15% of the delegate votes may force a primary, which would be held on August 9.

During the switch, an additional 56 delegates supporting August Wolf, changed their vote to Dan Carter.

[17] Carter was a decided underdog against Blumenthal, with nearly all handicappers rating the race as "Safe Democratic" or its equivalent.