Drea was elected to the Legislative Assembly of Ontario in the 1971 provincial election as the Progressive Conservative Member of Provincial Parliament for Scarborough Centre. He defeated incumbent New DemocratMargaret Renwick by 4,873 votes. Drea was re-elected with smaller pluralities in the 1975 and 1977 elections, and by a larger percentage in 1981. After serving for several years on the backbench, he was brought into the provincial cabinet of Bill Davis following the 1977 provincial election as Minister of Correctional Services. He initiated reforms in the province's system of jails, including the closure of the original Don Jail. On entering cabinet, Drea publicly revealed his battle with alcoholism, pledging to stop drinking in order to set an example for prisoners. In 1978, he was appointed Minister of Consumer and Commercial Relations. After the 1981 provincial election, he became Minister of Community and Social Services, and is credited with improving the status of people with disabilities. In September 1983 he was hospitalized with circulation problems. He briefly gave up his cabinet position from September 29, 1983 to November 21, 1983. Citizenship and Culture ministerBruce McCaffrey was named to act in his place during this time. He served in cabinet until Bill Davis retired as Premier of Ontario in 1985. Drea supported Roy McMurtry's bid to succeed Davis as party leader, and voted for Larry Grossman on the second ballot following McMurtry's elimination. He supported Frank Miller over Grossman on the third and final ballot. Drea explained that he had planned to support Miller after McMurtry's elimination, and only went to Grossman for one ballot on McMurtry's recommendation. He was not re-appointed to Miller's cabinet and instead served as parliamentary assistant to the premier. Drea was disappointed at being dropped from cabinet and decided not to run in the 1985 election. He said, "I'm not wanted so, I won't be running." He reflected on his time in politics. "I'm happy," he said. "I've had 14 marvellous years with Mr. Davis... the greatest living Canadian."
Cabinet posts
Later life
Drea was appointed to the Ontario Municipal Board by Miller in May 1985. His tenure there was short as Miller's successor, Liberal Premier David Peterson, appointed Drea as chairman of the Ontario Racing Commission four month later. Drea remained chairman until 1994 when Bob Rae's NDP government decided not to reappoint him. He would not speculate on the reason for dropping him from the position. "I don't know why they're doing it," he shrugged. "It's like ball players. You get hired. You get fired." During his tenure as chairman he introduced teletheatres for simulcasting races across the province and was responsible for saving racetrack operations in Windsor, Elmira and Sudbury. He died on January 15, 2003 from pneumonia.