Bill Nelson was born in Miami and lives in Orlando, Fla. He earned a bachelor's degree from Yale University and a law degree from the University of Virginia.
He served in the U.S. Army from 1968 to 1970.
Nelson served in the Florida Legislature from 1972 to 1978 before winning election to the U.S. House of Representatives in 1978. He won re-election five times before leaving to make an unsuccessful run for the Democratic gubernatorial nomination in 1990.
He spent four years in the private sector before returning to politics, winning election as insurance commissioner in 1994 and re-election in 1998. He was elected to the U.S. Senate in 2000.
Nelson and his wife, Grace, have two adult children.
Bill Nelson is seeking his third term in the U.S. Senate in 2012. He faces Republican U.S. Rep. Connie Mack in the November general election.
He won re-election to the U.S. Senate in 2006 with 60 percent of the vote. He defeated former U.S. Rep. Katherine Harris, who was mostly known for her role as Florida's top elections official in the chaotic 2000 presidential recount.
Nelson won the seat in 2000, defeating Orlando-area U.S. Rep. Bill McCollum. Both candidates spent more than $8.5 million.
He fought changes, in 2012, to Florida's voting laws enacted by the Republican governor and legislature, saying restrictions on voter registration and a reduction in early voting days was an attempt to suppress the Democratic vote.
In 2012, he introduced legislation designed to curb identity theft in the tax system. His home state of Florida contains the top two cities where fraudulent tax returns originate: Tampa and Miami.
He has been a leader in trying to prevent oil and gas exploration in the eastern Gulf of Mexico off Florida's coast. He announced plans in July 2010 to introduce legislation that would require the National Oceanic and Atmospheric Administration to develop a detailed plan for keeping track of, and attacking, suspended subsurface plumes from the Deepwater Horizon gusher.
In 2012, he pushed to have the bulk of the fines from the BP oil spill go to Gulf states for recovery efforts. He was also the Senate sponsor of legislation that would make it easier for military veterans to get jobs by streamlining professional licensing.
In April 2010, Nelson said the Chinese government should pay the homeowners' damages tainted by drywall imported from that Asian country.
He supports reforms that would allow illegal immigrants an opportunity to earn citizenship.
When the Democratic National Committee threatened to strip Florida of its delegates because it held its 2008 presidential primary too early, Nelson sued his own party to restore the delegates. The suit was thrown out, and Nelson later filed legislation that would reform the primary system. He was an early supporter of Hillary Clinton in the 2008 Democratic primary.
During his first term in the Senate, Nelson advocated a strong space program. Following the Columbia disaster, Nelson said Congress had cut too much funding to the space program. He voiced concern about a gap between the end of the shuttle program and the development of new spacecraft, saying it could mean layoffs and breaks in training.
Nelson paid special attention to the search for missing Navy pilot Scott Speicher in Iraq. The Jacksonville pilot's plane was shot down on the first night of the 1991 Gulf War.
Nelson voted for the Iraq war resolution in 2002, but later said he regretted that decision. He has also voted to delay military base closings and increase troop strength.
Nelson supported a measure to allow the federal government to intervene in the case of Terri Schiavo, a brain-damaged Florida woman who died in March 2005 after her life support was withdrawn.
During the aftermath of eight destructive hurricanes that hit Florida in 2004 and 2005, Nelson pushed for a federal program to let insurance companies set up catastrophe funds.
Committee Assignments: Commerce, Science, and Transportation; Finance; Special Aging; Select Intelligence; Budget
American Conservative Union Rating: 15
Americans for Democratic Action Rating: 90
Bill Nelson is not up for re-election in 2014.
(Last updated by The Associated Press on September 5, 2014.)