Republican Senate candidate Rick Scott, seen on election night, was holding onto a narrow lead that, if it is maintained, could require a recount. (Wilfredo Lee/AP)

Nearly two decades after hanging chads transfixed the nation, Florida is once again headed toward a high-stakes election recount, as vote margins narrowed in Democrats’ favor Thursday in the state’s marquee U.S. Senate and governor’s races.

Hundreds of party and interest-group volunteers spent the day trying to track down people who had cast provisional ballots, seeking affidavits to prove their votes should be counted. And in an echo of the 2000 presidential election, state Republicans tried to preempt the coming fight by accusing Democratic lawyers of heading to Broward County to “steal” the election.

In the Senate race, Gov. Rick Scott (R) had a lead of just more than 15,000 votes, or 0.18 percent, over Sen. Bill Nelson (D) as of Thursday night. In the governor’s race, Tallahassee Mayor Andrew Gillum (D) trailed former congressman Ron DeSantis (R) by more than 36,000 votes, or 0.44 percent.

Under Florida law, a statewide machine recount is conducted when the margin of victory is less than 0.5 percent, and a manual recount is ordered if the margin is less than 0.25 percent.

The likely recounts, however, are expected to be more orderly than the televised circus that resulted in George W. Bush’s election to the presidency. Under changes to state law, local canvass boards no longer have discretion over whether to order a recount, and new optical-scan voting machines have made it easier to divine voter intent than the old punch card ballots, which sometimes featured the partially detached bits of paper.

The recount preparations come as legal challenges have added suspense to statewide races in two other key states. Four county Republican parties in Arizona filed suit Wednesday to prevent county recorders from trying to verify signatures after polls closed for mail-in ballots in a U.S. Senate race in which Rep. Kyrsten Sinema (D) pulled into the lead over Rep. Martha McSally (R) on Thursday night.

In Georgia, the campaign of Democratic gubernatorial candidate Stacey Abrams, who is hoping to trigger a runoff election with Republican Brian Kemp, filed a federal lawsuit to allow for the counting of absentee ballots received before the close of business Friday. Kemp had overseen the election as Georgia’s secretary of state before resigning from the post Thursday.

Common Cause, a civil rights group, is seeking emergency relief that will give it more time to investigate all provisional ballots. The group also wants a federal judge to order Georgia to count all provisional ballots, unless the state proves that a voter was not eligible or did not register in time.

A runoff would be called in Georgia if neither candidate exceeds 50 percent of the vote. As of Thursday night, Kemp stood at 50.33 percent and Abrams at 48.7 percent.

The campaigns for Nelson and Gillum in Florida have become more optimistic in recent days as newly counted votes in Broward County increased their totals. They have told the state they plan to aggressively monitor any recounts.

“We believe at the end of the day, Senator Nelson is going to be declared the winner and is going to return to the United States Senate,” Marc Elias, an election lawyer representing the Nelson campaign, said in a conference call Thursday morning. “I think it’s fair to say right now the results of the 2018 Senate election are unknown.”

Scott responded hours later by accusing the election supervisors of Broward and Palm Beach counties of possibly committing fraud, though he did not provide evidence beyond his dwindling vote margin and alleged procedural errors.

“Every Floridian should be concerned there may be rampant fraud happening in Palm Beach and Broward counties,” Scott said as he announced legal action and called on state law enforcement to investigate. “I will not sit idly by while unethical liberals try to steal this election from the people of Florida.”

Nelson campaign spokesperson Dan McLaughlin responded after Scott spoke. “The goal here is to see that all the votes in Florida are counted and counted accurately,” he wrote in a statement. “Rick Scott’s action appears to be politically motivated and borne out of desperation.”

Earlier, the state’s other senator, Republican Marco Rubio, also accused Nelson’s team of trying to “steal” the election.

“Now democrat lawyers are descending on #Florida. They have been very clear they aren’t here to make sure every vote is counted,” Rubio added in one of a series of tweets. “They are here to change the results of election; & #Broward is where they plan to do it.”

Ronna McDaniel, the chair of the Republican National Committee, attacked the local elections supervisor for the time it was taking Broward to count ballots.

“What’s happening in Florida is unacceptable,” McDaniel wrote. “The #Broward Elections Supervisor has been pulling stunts like this for years and we’re not going to let her get away with it.”

The stakes were evident when the Gillum campaign, in a rare exercise in American politics, backed away from the candidate’s election night concession.

“On Tuesday night, the Gillum for Governor campaign operated with the best information available about the number of outstanding ballots left to count,” Gillum spokeswoman Johanna Cervone said in a statement. “Since that time, it has become clear there are many more uncounted ballots than was originally reported.”

Elias said during in the call that Democrats tend to gain votes in hand recounts. “It’s a jump ball,” he said of the Senate race.

Problems with delayed ballot reporting in Democratic-leaning Broward County, the epicenter of the recount dispute in the 2000 presidential election, have added to the uncertainty.

Democrats have raised concerns about the design of the ballot in Broward County, which ran more than 10 pages in some cases. They argued that it may have contributed to an undervote of more than 20,000 for the Senate race, compared to the governor’s race.

On the first page of the ballot, the Senate race was listed at the bottom of the page, under the voting instructions, while the governor’s race was listed in a separate column to the right of the instructions.

Lawrence Norden, who has studied voting technology at the Brennan Center for Justice, said the design could have contributed to Broward’s higher rate of under votes for the Senate race. “No other county had this high undervote rate,” he said.

Others suggested the reason for the undervote may have been more complex than simply bad design.

“I don’t think that is the sole reason for the undervote. It may have contributed,” said Broward County county Democratic chairwoman Cynthia Busch. “I think there is also an issue of voter information in an area of the county.”

She said that some parts of the county where the party spent less money to inform voters about the ballot had higher undervote rates.

Barry Richard, an attorney for Gillum who represented George W. Bush in the 2000 recount, said it was still too soon to know where the final vote will end up. “It is still a moving target,” he said.

Election supervisors have until noon Saturday to finish their initial count, which will determine whether a recount will be ordered.

That deadline sent Democrats in the state scrambling Thursday to resolve questions about provisional ballots that had been cast on Election Day. In some cases, voters were contacted in an effort to get affidavits with identification that proved their identity.

Marji Sachs, an attorney in Weston, Fla., has volunteered to clear provisional ballots. “It happened really quickly and it was semi-organized chaos,” she said.

Jeff Greene, the communications chair for the Broward Democratic Party, said there were several specific issues that party lawyers had flagged that would hopefully be resolved in a recount.

He said there had been about 10,000 ballots in Palm Beach County with stray marks that could have thrown off machines. In Miami-Dade County, he said, the rejection of mail ballots for non-matched signatures was at 2 percent, well above normal rates.

As night fell Thursday, the count of mail-in ballots in Broward continued, under heavy watch from partisans on both sides. “The Democratic and Republican Party both have an army of lawyers there,” Greene said.

That, too, was a reprise of the 2000 election. Lawyers flooded into the state then for a swirl of court fights and a recount that ended Dec. 12, more than a month after the Nov. 7 election, after a U.S. Supreme Court order.