Credico was formerly active on the comedy circuit, and at the age of 27 he made an appearance on The Tonight Show Starring Johnny Carson. During a later appearance he compared Ambassador Jeane Kirkpatrick to Eva Braun; he was never invited on the show again. Credico was featured on the comedy album, Strange Bedfellows: Comedy and Politics along with Jimmy Tingle, Barry Crimmins, and Will Durst. Credico spent four years in Tulia, Texas, bringing national attention to a racially charged mass drug arrest. The Kunstler Fund produced an award-winning documentary on the subject entitled Tulia, Texas: Scenes from the drug war, written, directed and edited by Emily Kunstler and Sarah Kunstler, the daughters of famed attorney William Kunstler. Credico is the subject of the film Sixty Spins Around the Sun, directed by comedian Laura Kightlinger. Credico produced, directed and wrote the radio program 60 Mimics, and is a frequent guest on Live from the State Capitol with Fred Dicker, a political talk radio program on WGDJ in Albany, New York.
Credico ran for the Democratic nomination for Mayor of New York City in the 2013 election. He received 12,685 votes. He also appeared on the ballot in the general election with 14 other candidates, on the Tax Wall Street line, receiving 654 votes.
2014 gubernatorial election
Credico challenged incumbent Democratic Governor Andrew Cuomo in the 2014 Democratic primary. He came in third among three candidates, with 20,760 votes.
Arranged by Margaret Ratner Kunstler, a mutual friend who is Julian Assange's attorney, Credico hosted Assange on Credico's August 25, 2016, radio show. On August 27, 2016, Credico sent a text message to Roger Stone that "Julian Assange has kryptonite on Hillary." Credico also notified Stone of subsequent releases by WikiLeaks of numerous emails stolen from John Podesta and the Hillary Clinton campaign, a publication which initiated on October 7, 2016. In November 2017, Stone told the House Intelligence Committee that Credico was his intermediary with Assange to obtain information on Hillary Clinton. Credico was then subpoenaed to appear before the committee, but asserted his Fifth Amendment right before the interview. The committee released him from appearing. By August 2018, special counsel Mueller had subpoenaed Credico to testify before a grand jury in September 2018. Credico intended to comply with the request. Mother Jones reported that Credico had received text messages from Stone in January 2018 stating that the latter was seeking a presidential pardon for Assange. In January 2019, Stone was arrested by the FBI. His indictment claimed that Credico, referred to as "Person 2", was not Stone's sole contact with WikiLeaks. It also claimed that Credico was pressured by Stone to "stonewall" his testimony before Congress, and to "do a Frank Pentangeli." Among other statements, Stone told Credico to "prepare to die", and that he would "take that dog away from you." Credico relies on a medical support dog. Credico subsequently testified against Stone during Stone's trial in November 2019.