Tim Johnson was born and raised in Canton, S.D., and now resides in Vermillion. He attended the University of South Dakota, where he earned bachelor's, master's and law degrees.
Johnson was due to enter the U.S. Army in 1969, but was honorably discharged before he began basic training after doctors at a base in Fort Riley, Kan., found a tumor in his left ear.
Johnson opened his law practice in Vermillion in 1975. Three years later he was elected to the state House and then to the state Senate.
He was elected to the U.S House in 1986, replacing Tom Daschle when Daschle won election to the U.S. Senate. He served five terms in Congress before winning election in 1996 to the U.S. Senate.
Johnson and his wife, Barbara, have three children.
Tim Johnson's political and personal futures were thrown into doubt on Dec. 13, 2006, when he had surgery to stop bleeding in his brain.
He was diagnosed with arteriovenous malformation, a condition that causes arteries and veins to grow abnormally large, become tangled and sometimes burst. After physical and speech therapy, Johnson returned to the Senate on Sept. 5, 2007, and then announced he would run for re-election.
Johnson won re-election in 2008, defeating Republican state Rep. Joel Dykstra with 62 percent of the vote. Johnson refused to debate during the 2008 campaign because he said his slow speech did not reflect his intellect.
He had a standard response to questions about his health during the campaign, saying he believes he has been given a second chance in life and wants to use it to help the nation and his home state. "I'm back up in the saddle," he said in October 2008.
Johnson's speech has continued to improve, but he uses a motorized scooter to get around. He became chairman of the Senate Banking Committee in January 2011.
The Democratic senator has not revealed whether he will seek re-election in 2014, but at least one potential challenger has emerged. Former Republican Gov. Mike Rounds has said he is seriously thinking of running for the Senate seat in 2014.
In recent years, Johnson has generally supported positions taken by Senate Democrats and President Barack Obama. He supports ending tax breaks for the wealthy and getting rid of subsidies for oil companies. When the U.S. Supreme Court upheld the 2010 health care bill in June 2012, Johnson called it a "huge win for South Dakotans and the nation."
Johnson also emphasizes his success in getting money for water projects and other South Dakota programs.
He was diagnosed earlier in his career with prostate cancer and had surgery to remove his prostate gland in 2004. He later reported that tests indicated the cancer had not spread.
Johnson faced a delicate political situation in 2005, when Republican John Thune became South Dakota's other senator. Johnson had narrowly defeated Thune during a bitter campaign in 2002. Johnson and Thune wound up working together closely on many issues, including the bipartisan effort that saved Ellsworth Air Force Base from being closed.
Johnson has amassed a generally liberal voting record on Capitol Hill, although he calls himself a middle-of-the-road Democrat.
His political career has focused on parochial issues for prairie voters, such as authorizing spending on rural drinking-water projects, financial safety nets for farmers, drought aid to farmers and ranchers, Social Security benefits and veterans' health care.
Johnson has been a leading supporter of the requirement that meat carry a label indicating its country of origin, and he was the prime author of Senate legislation that bans meatpacking companies from owning livestock for any reason other than slaughter — a critical issue in beef-rearing South Dakota.
He has worked on American Indian issues and has promoted the increased use of ethanol to benefit South Dakota corn growers.
Johnson voted against the 2008 $700 billion bailout for the financial industry, but voted for the 2009 approximately $800 billion economic stimulus package, saying it was needed to boost the economy and create jobs.
Johnson has several moderate positions to which he can point. He is opposed to federal funding for abortions except in cases of rape, incest or threat to the life of the mother. He voted for the ban on the late-term abortion procedure referred to by critics as partial-birth abortions, and he was one of 11 Democrats in the Senate who voted for President George W. Bush's $1.3 trillion tax cut in May 2001.
President Obama named Johnson's son, Brendan, the U.S. attorney for South Dakota in 2009. The senator said he took no part in the nomination process.
Committee Assignments: Appropriations; Banking, Housing, and Urban Affairs(Chair); Energy and Natural Resources; Indian Affairs
American Conservative Union Rating: 5
Americans for Democratic Action Rating: 95
Tim Johnson is not seeking re-election in 2014.
(Last updated by The Associated Press on June 11, 2014.)