For months, Democrats have counted on demographic shifts to help former Secretary of State Hillary Clinton lock down Florida's 29 electoral votes in the race for the White House.
Heavier turnout among Latinos repelled by the rhetoric of Republican presidential nominee Donald Trump, in particular, would reassemble the coalition that elected and then re-elected President Barack Obama in 2008 and 2012.
But along the way, another group key to Obama's victories appears to have lost some enthusiasm: Black voters, who turned out in historic numbers to elect an African-American to the presidency, are showing up in lower numbers for early voting than they did four years ago. The question is whether the slide can be reversed, or at least tempered.
It is not a problem confined to Florida. Obama appeared Wednesday on the national "Tom Joyner Morning Show" in an attempt to fire up his supporters.
"Right now, the Latino vote is up. Overall vote is up," Obama said. "But the African-American vote right now is not as solid as it needs to be."
But in Florida, the stakes might be higher. Obama won the state by just 74,000 votes out of nearly 8.5 million cast in 2012, defeating GOP nominee Mitt Romney by less than 1 percentage point.
The most concrete reasons for Democrats to worry is lagging turnout for in-person early voting, a preferred method of casting ballots for many African-Americans. After the first eight days of early voting in Florida this year, about 15 percent of in-person early votes came from black voters, according to University of Florida political-science professor Dan Smith. That number was about 24.6 percent four years ago.
Democratic strategist Steve Schale, who ran Obama's campaign in the state in 2008, cautioned against panic but acknowledged cause for concern.
"I definitely think that we need to increase the level of urgency to vote," he said.
Others are less sanguine. Leslie Wimes, founder of the Democratic African-American Women's Caucus and an early critic of the Clinton campaign's outreach to black voters in Florida, has pointed to the low turnout as a sign she was right. She told MSNBC on Tuesday that it was too late for the campaign to correct its course.
"It's over now as far as the African-American community is concerned," she said.
Democrats who are more supportive push back by noting that there are more early voting days in Florida this year than in 2012 and that there will another weekend for "Souls to the Polls" drives by churches and other attempts to turn out black voters. Smith said that will likely shift the numbers.
"I expect (turnout) to go up with the final Saturday and Sunday," Smith said in an interview this week. "But if it doesn't go up, it basically shouts the lack of enthusiasm among African-Americans for the Democratic top of the ticket."
In a post on his blog Wednesday, Smith noted that African-American voters seemed to be getting out early and voting by mail in Miami-Dade, Broward and Palm Beach counties, suggesting that "the dire warnings of low black turnout may be premature."
Clinton's campaign has ramped up efforts to draw black voters to the polls in the closing weeks of the campaign. In Fort Lauderdale on Monday, Clinton delivered a speech targeted at African-Americans in which she promised "to continue to knock down those barriers that stand in the way of people being able to fulfill their potential."
Meanwhile, Obama and other high-profile black surrogates have been crisscrossing the state. Civil-rights legend and Congressman John Lewis and television and movie actress Aja Naomi King held events Tuesday and Wednesday to encourage voters to get to the polls, preferably early.
Democrats don't necessarily expect turnout for Clinton to exceed or even match the turnout among black voters for Obama, the first black president.
"Trying to compare a moment in history with anything else is just not a fair comparison," Schale said.
State Sen. Audrey Gibson, a Jacksonville Democrat who has long supported Clinton, compared Obama's first election in 2008 to the thrill of riding a bicycle for the first time; future rides seem less dramatic by comparison.
"It's nothing personal against Hillary Clinton," said Gibson, who is African-American. "It's just that it has a different feel."
Obama told Joyner that kind of reasoning shouldn't deter black voters, warning that a victory by Trump could lead to his administration's accomplishments being overturned.
"I need everybody to understand that everything we've done is dependent on me being able to pass the baton to somebody who believes in the same things I believe in," Obama said.