An unprecedented statewide hand recount is now under way in the Sunshine State, further extending a high-stakes, partisan battle over every last vote in Florida's crucial U.S. Senate race.

Following a five-day machine recount of the more than 8.3 million votes cast in the Nov. 6 elections, Secretary of State Ken Detzner ordered hand recounts Thursday afternoon in the race between U.S. Sen Bill Nelson and Gov. Rick Scott, and also the race for agriculture commissioner between Nicole "Nikki" Fried and Matt Caldwell.

The order gives canvassing boards in the state's 67 counties three days to pore over thousands of ballots that were rejected by machines because of "overvotes" — a voter appears to have chosen more than one candidate in a race — or "undervotes," in which a voter appears to have skipped a race altogether. With the help of state guidelines, the canvassing boards, which are allowed to enlist the help of volunteers, will try to determine how these voters intended to vote.

It's not entirely clear how many such overvotes and undervotes exist in the U. S. Senate race. A Times/Herald analysis of state and county data shows the number could be between 35,000 and 118,000 But the determination on how those ballots were cast — and the ability of the state's elections supervisors to get through all the ballots — could go a long way toward deciding whether Nelson is reelected or Scott ascends from governor to U.S. Senator.

Thursday's order has been expected for at least a week. Elections supervisors around the state began bracing for automatic recounts in the hours after the polls closed on the midterm elections, as late-breaking returns out of heavily Democratic Broward and Palm Beach counties slimmed leads by Scott, Caldwell and GOP gubernatorial nominee Ron DeSantis.

Florida law requires a machine recount for any race decided by one half of one percentage point or less, and all three races were within the margins when elections supervisors submitted their unofficial results Saturday to the state. As required by law, Detzner quickly gave the state's canvassing boards five days to run their voting totals again in the three races to confirm whether any fell within one quarter of one percentage point, the margin by which Florida law requires a hand recount.

DeSantis' lead held Thursday as the counties reported their tallies, keeping him above the quarter-point threshold and making him Florida's governor-elect barring a legal challenge from Andrew Gillum. But, as expected, the margins in the U.S. Senate and agriculture commissioner races remained under the threshold, requiring hand recounts of overvotes and undervotes.

Now, the canvassing boards and teams of at least two volunteers — with at least one Republican and one Democrat on each team — will pore over thousands of ballots and report back to Detzner. State law requires that the state's canvassing boards conclude that process by Sunday, so that Florida's elections canvassing commission can certify the results of the election by Tuesday.