He's not just an actor turned Senator turned actor. He has a long history in politics.
He was one of the counsel to the Senate Watergate Committee; you'll see him in archival footage that was used in the film "JFK". He also asked one of the key questions during those hearings: "Mr. Butterfield, were you aware of the existence of any listening devices in the Oval Office of the President?" Thompson's acting career started by playing himself in a minor film "Marie" based on actual incidents in a case he brought against the Tennessee Parole Board and the Governor of Tennessee (the producers couldn't find anyone to play him convincingly). He served in the US Senate for nine years before resuming his acting career, and at one point was ranking minority member.
More recently, he was one of those introducing Bush at the Republican National Convention in 2004. He'll be a serious contender if he decides to run; a lightweight he is Not.
His wife's position is rather interesting for a spouse with Presidential ambitions:
Worked as a shoe salesman, truck driver, and even a factory worker prior to becoming a lawyer.
When he joined the cast of "Law & Order" (1990) in the fall of 2002, Thompson (District Attorney Arthur Branch) became the first serving U.S. Senator to take a regular TV acting job. His term did not end until January 2003.
2nd wife Jeri, 35, is a political media consultant at Verner Liipfert law firm in Washington, who once worked for Senate Republican Conference and Republican National Committee.
http://www.imdb.com/name/nm0000669/bio More here:
http://www.ocala.com/apps/pbcs.dll/article... 
