Gallo was elected to the Parsippany-Troy Hills Township Council in 1967, and served as Council President from 1968-71. He was elected to the Morris County Board of Freeholders in 1971 to fill an unexpired term, and elected to a full three-year term in 1972. He was the Freeholder Director from 1973-75. In 1974, Gallo considered running for Congress in the 5th district, which included parts of Morris, Somerset, Essex and Mercer counties. The Republican incumbent, Peter Frelinghuysen, was retiring after 22 years. He instead endorsed Assembly Minority LeaderThomas Kean, who narrowly lost the GOP primary to Millicent Fenwick.
In 1975, Gallo became a candidate for the New Jersey General Assembly in the 24th Legislative District, which included part of Morris County and Summit in Union County. Gallo won the Republican primary by a more than 2-1 margin against four other candidates, W. Thomas Tintle, Gerard R. Hughes, Jack Newberger and Raymond F. Bonnell. In the general election, he defeated two-term Democratic Assemblyman John J. Sinsimer by 6,605 votes, 26,277 to 19,672. Gallo faced Sinsimer again in 1977 and won by an even greater margin, 15,505 votes, 33,306 to 17,801. He was re-elected by equally impressive margins in 1979, 1981, and 1983. Gallo was elected Assembly Minority Leader in 1981 and was re-elected to a second term in 1983.
U.S. Congressman
New Jersey's congressional map drawn after the 1980 census was thrown out in 1984 on the grounds that the variations in district populations were too large. A panel of federal judges substituted a new map that significantly altered the 11th District, home to 11-term Democratic incumbent Joseph Minish. Democratic-tilting towns in Essex, Hudson, southern Bergen and Passaic counties were cut out. To make up for the loss in population, the district was pushed further into heavily Republican Morris County, and also absorbed several equally Republican areas in Sussex and Warren counties while retaining the more Republican areas of Essex County. Gallo immediately jumped into the race; the redrawn 11th included his home in Parsippany. Minish was thought to face very difficult odds for reelection, but opted to run in the 11th after considering a run in another district. Ultimately, Gallo defeated Minish by 27,624 votes, 133,662 to 106,038. He was undoubtedly helped by Ronald Reagan's landslide reelection bid that year. Gallo's campaign was managed by Assemblyman Bob Franks. He was easily re-elected in 1986, 1988, 1990 and 1992 in what became one of the most Republican districts in the Northeast. Gallo served on the House Appropriations Committee, and joined the House Republican leadership as a Deputy Minority Whip. In 1994, Gallo faced a primary challenge from Dr. Joseph Pennacchio, a considerably more conservative Republican. Pennacchio spent over $200,000 of his own money attacking Gallo. Gallo won 26,492 to 10,917 in a four-candidate race.
Illness, death and legacy
The 1994 primary turned out to be Gallo's final campaign. He had been treated for prostate cancer in 1992 and the cancer returned in 1994. He withdrew as a candidate for re-election on August 29, 1994, and died on November 6, 1994 at age 58. Assemblyman Rodney Frelinghuysen was named to replace Gallo on the ballot, and was elected two days after Gallo's death. The Dean and Betty Gallo Prostate Cancer Center at the Cancer Institute of New Jersey is named in his honor.
