Fagan is known for his off-the-cuff remarks, illustrated by his characterization in the Boston Herald as “an outspoken lawmaker and defense lawyer.”[3] In one instance, Fagan's local newspaper, the Taunton Gazette notes that Fagan's “brash and quick wit”[8] is viewed by some observers as a “propensity for occasional over-the-top outbursts.”[8] In 1992, incumbent Representative Marc Pacheco decided to run for Massachusetts Senate, leaving open his 3rd Bristol District seat in the Massachusetts House of Representatives.

Fagan ran in the Democratic Party primary for the seat, facing opponents Carol Doherty, Gail Tardo, Alfred Baptista Jr, and George Bertoldo.

Due to the results of the 1990 United States Census, the boundaries of Fagan's districts were altered slightly prior to the 1994 election.

Running for re-election, Fagan faced no opposition in the Democratic primary or the general election, and thus secured a second term in the House.

[13][14] Fagan's path to a fourth term was easy again in 1998, as he was re-elected without any opposition in the primary or general election for the third consecutive cycle.

[15][16] In 2000, Fagan again faced no opposition in the primary or general election, securing a fifth term with relative ease.

[20][19] Seeking a seventh term in 2004, Fagan faced only trivial opposition in both the primary and general elections, winning with over 99% of the vote in both contests.

[21][22] Fagan yet again faced only minor opposition in the 2006 primary and general campaigns, prevailing with over 99% of voters for both elections.

As a defense attorney, Fagan argued, he would have no choice but to interrogate the victims, stating, I'm gonna rip them apart.

The contentious campaign came to a head when, during a debate between the candidates, Fagan questioned O'Connell's ability to count, a charge that was viewed by some as sexist.

[31] The Taunton Gazette endorsed Fagan in the days prior to the election, citing his experience in the House and track record as a lifelong Tauntonian with deep ties to the community.

[28] Both candidates requested a recount,[32] the results of which showed O'Connell indeed defeating Fagan, albeit by a slimmer margin of only 31 votes.

I'm a citizen who's fed up with this bullbleep just like everybody else.”In the early morning hours of 3 February 2008, Fagan's son Kevin was killed after accidentally slipping and falling from the Washington Bridge in East Providence, Rhode Island, which was under construction at the time.