Lucey served as justice of the peace in Ferryville, Wisconsin in 1946. He also served on the De Soto School Board and was board treasurer in 1946. Lucey served in the Wisconsin State Assembly from 1949 to 1951. From 1957 to 1963 he served as state chairman of the Democratic Party. Lucey was a Wisconsin campaign aide of John F. Kennedy in his presidential run in 1960. In 1964, Lucey was elected Lieutenant Governor of Wisconsin and served one term from 1965 to 1967. At this time the governor and lieutenant governor of Wisconsin were elected on separate tickets, and voters chose Lucey, a Democrat, as lieutenant governor while simultaneously electing Republican Warren P. Knowles as governor. Lucey ran as the Democratic candidate for governor of Wisconsin in 1966 but failed to unseat incumbent Warren Knowles. He was initially a supporter of Senator Robert Kennedy in his 1968 presidential bid, but began working for Senator Eugene McCarthy's presidential campaign following Kennedy's assassination. He was the acting director of the McCarthy campaign at the 1968 Democratic National Convention. In 1970, Lucey campaigned again for governor and was elected with 54 percent of the vote. Lucey was the first Wisconsin governor elected to a four-year term after a 1967 amendment to the state constitution extended terms from two years to four. He took office on January 4, 1971. Lucey ran successfully for a second term as governor in 1974, but he resigned effective July 6, 1977 to accept a nomination as United States Ambassador to Mexico.
University of Wisconsin System merger
One of Lucey's executive initiatives was to revive an idea to merge the state's two university systems, the Wisconsin State University system and the University of Wisconsin System, with campuses at Madison, Milwaukee, Green Bay, and Parkside, as well as the University of Wisconsin–Extension. The idea was suggested in the 1940s and 1950s by Governors Oscar Rennebohm and Walter J. Kohler, Jr. In 1971, Lucey raised the issue again, saying a merger would contain the growing costs of two systems; give order to the increasing higher education demands of the state; control program duplication; and provide for a united voice and single UW budget. Madison faculty and administrators by and large opposed the merger, fearing it would diminish the great state university. Most WSU faculty and administrators favored the merger, believing it would add prestige to their institutions and level the playing field for state funding. Merger legislation easily passed the Democratic-controlled Assembly. After much maneuvering and lobbying, it was approved by a one-vote margin in the Republican-controlled Senate. It took until 1974 for implementation legislation to be finalized. "I had to be pretty heavy-handedno merger, no budget," said Lucey in an interview following his term in office.
Other gubernatorial accomplishments
Lucey also recommended additional funding for tourism, which spurred development throughout the state. Two examples were the expansion of the Wisconsin Department of Natural Resources park system and the Mt. Telemark Resort in Cable, Wisconsin. Since 1974, Cable and Mt. Telemark host the American Birkebeiner each year, the largest cross-country ski race in North America. He appointed a number of task forces to address minority concerns, including the Governor's Investigating Committee on Problems of Wisconsin's Spanish Speaking Communities, which identified the lack of programs to address the Mexican American and Puerto Ricans' lack of access to education, health, housing, and work across the state. At a time when there were over 30,000 Mexican Americans living in Wisconsin, with half living in Milwaukee, less than 10 Mexican Americans were enrolled at UW-Milwaukee.
1980 vice presidential campaign
The John Anderson—Patrick Lucey presidential ticket received 5,719,437 votes for 6.6 percent of the total vote in the 1980 presidential election, despite a 25% showing in early polls by Anderson and a spirited televised debate between Anderson and Ronald Reagan.
In 2011, Lucey, although a Democrat, acted as David Prosser's campaign co-chairman. On March 31, 2011, he resigned from Prosser's campaign and endorsed JoAnne Kloppenburg, attributing his decision to Prosser's "disturbing distemper and lack of civility", while praising Kloppenburg for " throughout the campaign to even-handedness and non-partisanship and both promising judicial temperament and good grace, even in the heat of a fierce campaign."
Death
Lucey died on May 10, 2014, in Milwaukee, Wisconsin at the age of 96.