Florida voters surged to the polls on Sunday, shattering all-time turnout records in at least three of the battleground state’s most populous and heavily Democratic counties on the final day of early voting.

Victory in Florida is essential for Republican nominee Donald Trump to have any chance of winning the White House. But analysts said the voters who turned out in historic numbers this weekend have likely given Hillary Clinton, the Democratic nominee, a critical edge heading into Election Day.

“I do believe this thing is tracking towards a Clinton victory,” wrote Steve Schale, a respected Florida Democratic strategist who has been following early returns closely.

A Republican consultant in the state, David Johnson, said he believed Clinton could win by as much as three points, thanks in part to the shortcomings of his own party’s get-out-the-vote efforts.

“We used to have a great statewide operation,” Johnson told the Naples Daily News. “Now I’m not convinced that’s going on, because I don’t see the evidence. And I see it on the Democrats’ and their allies’ side.”

Souls to the polls invocation outside Miami-Dade County Hall early voting site pic.twitter.com/CJdWoyQ4ZE — Patricia Mazzei (@PatriciaMazzei) November 6, 2016

Roughly 6.4 million people voted early in Florida, a record high number that will likely make up about two-thirds of this year’s total electorate, experts said. President Barack Obama won the state in 2012 by just 74,000 votes.

One week ago, early returns had Democrats fretting. Turnout among black voters was lagging, and while Latinos were submitting ballots in large numbers, so were white voters seen as more likely to support Trump.

Those trends shifted during the last four days. Black turnout jumped substantially, boosted by Obama’s multiple Florida visits and Sunday’s “souls to the polls” voting drive led by black churches.

Black turnout in Florida will end up higher than in 2012, Daniel Smith, a University of Florida political science professor and election data analyst, predicted on Sunday.

I do believe this thing is tracking towards a Clinton victory. Steve Schale, Florida Democratic strategist

Meanwhile, the state’s Latino turnout accelerated. The number of Latinos who voted in person through Saturday was up fully 100 percent from 2012. It appears likely that more Latinos in Florida will have voted early in 2016 than they voted overall in 2012.

Smith also noted that 36 percent of the 907,000 Latinos who have voted this year didn’t vote at all in 2012. “That’s a full 12 points higher than whites, and will likely be the key to who wins the presidency,” he said.

FL #earlyvote Race change vs 2012 via @electionsmith

Afr-Am +70.6K (+9.2%)

Hisp +453.8K (+86.9%)

White +900K (+27.2%)

Other +121.5K (+48.3%) — Michael McDonald (@ElectProject) November 7, 2016

Joshua Roberts/Reuters On Sunday, President Barack Obama rallied supporters in Kissimmee, Florida.

Over 53,000 ballots were cast on Sunday alone in Miami-Dade, Florida’s most populous county and a Democratic stronghold, smashing the previous all-time daily record of 42,810 that had been set on Friday.

Well over 80 percent of Miami-Dade residents are Latino or black, and total early voting in the county went up 61 percent compared to 2012.

In Broward, the state’s second most populous county, a record-setting Sunday capped off an early voting period that saw returns increase 47 percent from 2012. Democratic-leaning Orange County also set a single-day turnout record on Sunday.

Slightly more registered Democrats than Republicans have voted in Florida thus far, but Democrats’ advantage is lower than it was at this point in 2012 ― and historically, more Republicans vote on Election Day in Florida.

Yet analysts said Democrats should receive a larger-than-normal boost this year from voters with no party affiliation, who are expected to make up one-fifth of the electorate. In 2016, that bloc of voters has been significantly less white and more Latino and Caribbean than the electorate as a whole.

Correction: An earlier version of this story identified Miami-Dade and Broward as Florida’s largest counties. They are the state’s most populous counties, but not, in geographic terms, the largest. This story was also updated Monday morning with new information about Florida’s early voting returns.

HUFFPOST READERS: What’s happening in your state or district? The Huffington Post wants to know about all the campaign ads, mailers, robocalls, candidate appearances and other interesting campaign news happening by you. Email any tips, videos, audio files or photos to scoops@huffingtonpost.com.