Silipo was elected to the Legislative Assembly of Ontario in the 1990 provincial election as the New Democratic PartyMember of Provincial Parliament for the Toronto riding of Dovercourt. He joined the Bob Raecabinet as Chair of the Management Board from July 31, 1991 to September 23, 1992, Minister of Education from October 15, 1991 to February 3, 1993 and Minister of Community and Social Services from February 3, 1993 to June 26, 1995. As Education Minister, one of Silipo's first decisions was to restore national indicator achievement tests, which had previously been removed by his predecessor, Marion Boyd. He was also an active promoter of "de-streaming" in an effort to stop the practice of "streaming" children of immigrant and working-class families into non-academic courses of study. Although Silipo supported the Rae government's austerity Social Contract legislation in 1993, he was generally regarded as one of the more left-leaning figures in the cabinet. In 1991, he was the only member of Rae's inner cabinet to recommend that the government introduce public automobile insurance to the province. In 1994, he spoke in cabinet against cuts to social assistance and the introduction of user fees for certain prescription drugs. Silipo retained his seat in the 1995 election that defeated the Rae government. He ran for the leadership of the NDP in 1996, but was unable to build a strong support base and finished fourth behind Howard Hampton, Frances Lankin and Peter Kormos. Following the contest, Silipo was appointed deputy leader of the party. In 1997, when the provincial government was passing a bill that would amalgamate the city of Toronto with surrounding municipalities, the NDP attempted to block the bill by filibuster. Silipo introduced a list of 11,000 amendments, to be debated and voted on one at a time, which held up the bill for a week and a half. In 1999, a reduction in ridings in Ontario resulted in the elimination of the Dovercourt riding. Silipo contested the new riding of Davenport in the 1999 election against Liberal Tony Ruprecht. He lost by nearly 5,000 votes.
Cabinet positions
Later life
He was appointed to the Workplace Safety and Insurance appeals tribunal by Labour MinisterChris Stockwell in 1999. In 2003, he became president of the newly formed Federation of Calabrese in Ontario. He died in 2012 after being diagnosed with a brain tumour. He was 54.