Halpin grew up on Long Island and attended St. Joseph's School in Babylon.
[2] Halpin's own political career began at age 26 in 1979, when he was elected to represent the 13th District of the Suffolk County Legislature.
He was re-elected three times and remained in the Assembly until 1987, sitting in the 184th, 185th, 186th and 187th New York State Legislatures.
[5] In 1994, Halpin became Executive Vice President at the Institute for Student Achievement,[6] located in Lake Success on Long Island.
On December 18, 2018, Halpin was appointed as the Chair of the SCWA to replace Jim Gaughran, who resigned upon his election to the New York State Senate.