UPDATE: The Florida Senate race between incumbent Democrat Bill Nelson and Gov. Rick Scott (R) is heading for a recount that could begin as soon as Wednesday.

Scott claimed victory Tuesday night, but Nelson said Wednesday that he would not concede.

Florida state law triggers a recount ordered by the secretary of state when the margin of victory is 0.5 percent or less. According to unofficial results, Scott leads Nelson by 0.42 percent.

PREVIOUSLY:

Florida Gov. Rick Scott has ousted Democratic Sen. Bill Nelson , a big step toward Republicans hopes of hanging onto and even building on their majority in the U.S. Senate .

Scott, 65, will join Marco Rubio in Washington in January, giving the state two Republican senators for the first time since Reconstruction. Nelson, 76, had been seeking his fourth six-year term following his stint as the states insurance commissioner and, before that, 12 years in the House as a congressman from the Space Coast.

Scott is finishing out two terms as the states chief executive and could not seek a third because of term limits. He was seen as among the GOPs strongest recruits to take away Democratic-held Senate seats, and his victory likely makes it impossible for Democrats to win back the chamber this election.

Scotts two previous election victories had been squeakers 1.1 percentage points each time and his Senate victory will likely be even narrower, less than 1 percentage point, by the time all the votes are counted.

Florida now has three times elected to statewide office the man who in the 1990s ran the for-profit hospital chain that agreed to pay $1.7 billion in fines for systematically defrauding Medicare, Medicaid and veterans health programs. Scott invoked his Fifth Amendment right not to incriminate oneself 75 times during a deposition in a related civil trial about his role in the fraud committed by Columbia/HCA.