Thompson, often credited with transforming the Badger State into a national political player, is leaving his lifelong home state for Washington after spending years on the fringes of national politics.
Thompson has been nominated by President-elect Bush for secretary of health and human services. The selection was not unexpected; Thompson played a central role in the Bush campaign, serving as platform chair at the Republican National Convention and acting as Bush's campaign chairman in Wisconsin.
Thompson, 59, seems like a natural fit for the health and human services spot with his reputation for being innovative in areas such as health care and welfare reform.
Wisconsin was at the forefront of welfare reform under Thompson's administration. It was the first state to apply and receive approval from the federal government for its work-based welfare reform proposal.
Wisconsin Works, or W-2, went into effect in 1997. It was the culmination of a decade of reform experiments in Wisconsin. It requires adults to work or get job training in exchange for a check, medical assistance and subsidized child care.
President Clinton called W-2 "one of the boldest most revolutionary welfare reform plans in the country." Thompson and others have touted the program as a model for the nation.
More than 28,300 people have left Wisconsin's welfare rolls since August 1997, although critics say that doesn't guarantee they are getting the education they need or earning wages above the poverty level.
Ed Garvey, who ran against Thompson in 1998, said W-2 is a "program without a heart."
Thompson also received federal waivers to institute a health care program for the poor, BadgerCare, that provides insurance to people who don't make enough to afford private insurance but make too much to qualify for Medicaid, the federal insurance program for the poor.
In taking over health and human services, Thompson will succeed Donna Shalala, who once worked for him as the University of Wisconsin chancellor.
The two have clashed over changes to the nation's transplant system proposed by HHS, which would break down geographical barriers governing how organs are distributed. The state sued HHS over the proposals, but a federal judge threw out the case last month.
Thompson, Wisconsin's longest-serving governor, had hinted he might run for a fifth term in 2002, but rumors about a possible cabinet position were flying well before the election.
Thompson has flirted with the idea of going to Washington before. He considered running for president himself this year but dropped the idea, saying he didn't have the necessar financial backing or support. He ran for Congress in 1979 but lost in the Republican primary.
Despite those forays into national politics, Thompson has repeatedly said he likes being governor and would need a good reason to leave the state of Wisconsin, where he has lived his entire life.
"I'm not looking for any other jobs. I've got a big one in front of me putting a budget together and taking care of things in the state of Wisconsin," he said in late November.
The governor has been a strong proponent of states rights, writing in his 1996 book "Power to the People," that he was convinced "most government officials in Washington actually have two mouths and one ear."
During his tenure, Thompson has won strong approval in a state that has voted for a Democratic presidential nominee in the last four elections, including the last one. Observers say that's due largely to the governor's down-home, folksy style.
There were only 1,500 residents in Thompson's hometown of Elroy, where 6-year-old Tommy helped his father in the family's gas station and general store.
"He is a guy that most people would be glad to have a beer with. He's able to communicate at a very basic and understandable level," said Madison lawyer Don Bach, a former Thompson chief of staff.
"Having been there at the beginning, I can tell you that Tommy Thompson is tireless. ... He is an enthusiastic cheerleader for Wisconsin," he said.
Thompson's brother, Ed, is a colorful character himself. He played professional poker in Las Vegas, fought in boxing matches, owned a grocery store and tangled with the law over video gambling at his supper club. He is now mayor of Tomah, some 20 miles down the road from Elroy.
Since Thompson was elected in 1986, Wisconsin's economy has steadily improved. The 1999-2001 budget included $1.1 billion in tax relief and measures to encourage biotechnology. The state's unemployment rate has remained below the national average for more than 12 years.
Thompson pushed the Milwaukee School Choice program, in which religious and private schools receive up to $5,000 per pupil from the state to cover tuition for low-income Milwaukee students who otherwise would attend public schools. Bush has been a proponent of school vouchers.
Thompson got his bachelor's degree from the University of Wisconsin-Madison. As a third-year law student there in 1966, he ran for state Assembly and beat the 16-year Republican incumbent in the primary before winning the general election.
Thompson credited luck and pluckiness for his win. While the incumbent was on a two-week Alaskan cruise before the election, Thompson traveled through his home district and knocked on every constituent's door.
For the next 20 years, Thompson served in the Assembly while practicing law part-time. He was first elected governor in 1986, when he got 53 percent of the vote to beat Democraic Gov. Tony Earl. Thompson became the first Wisconsin governor elected to three successive terms, then won another in 1998.
While keeping his reputation as a moderate Republican, Thompson has appeased the conservative factions of the party without being a firebrand on explosive social issues such as abortion.
Thompson is pro-life, but he supports exceptions in cases of rape or incest or where the woman's life is at stake.
Thompson is former chairman of the National Governors' Association and the Republican Governors' Association and is currently chairman of the Amtrak Board of Directors.