President Obama is headlining a pair of campaign rallies for Hillary Clinton in Florida on Thursday. It's part of a concerted effort to mobilize the African-American vote, amid signs that early black turnout lags the pace of four years ago.

In some states, like North Carolina where Obama campaigned Wednesday, Republicans deliberately tried to limit access to early voting — a move that was only partially reversed by the federal courts.

But even in Florida, where opportunities for early voting have expanded in the last four years, black turnout is lagging in a way that could hurt Democrats.

"If the Clinton campaign is waiting till Tuesday, November 8th, to get out the black vote, they have some heavy lifting to do," said University of Florida political scientist Daniel Smith who tracks early voting as Election Smith.

Obama acknowledged a black "enthusiasm gap" compared to 2012.

"I know there are a lot of people in barbershops and beauty salons and in the neighborhoods who are saying to themselves, 'Well, we love Barack, and we especially love Michelle,'" Obama said this week in an interview with Tom Joyner's syndicated radio program. "And so it was exciting, and now we're not excited."

Obama is trying to gin up some excitement, telling Joyner's largely African-American audience he doesn't want to spend his last months in office contemplating the dismantling of everything he's done.

"All the work we've done to make sure people get overtime," he said. "All the work we've done to make sure women get paid the same as men for doing the same job. All the work we've done to make sure 20 million people have health insurance."

African-Americans have seen some of the biggest gains in health insurance under the Affordable Care Act, gains that could be quickly wiped away if Donald Trump wins the White House.

Democrats can point to some encouraging signs. African-American turnout in southeastern Florida has picked up in recent days. And turnout among Hispanic voters in Florida is running ahead of 2012's pace.

"That is probably the silver lining right now for the Clinton campaign is the high rate of Hispanic turnout," said political scientist Smith. "Especially in the central part of the state — mostly Puerto Ricans. Polling numbers suggest Hispanics, especially Puerto Ricans, are strongly against Donald Trump."

But Democratic margins among Hispanic voters are not as lopsided as with African-Americans so it takes a big jump in Hispanic turnout to offset any decline in black voting.

Obama cautions any voter who stays home out of apathy is doing the work of voter suppression groups for them. And in hard-fought states like Florida and North Carolina, even a small change in turnout can make a big difference.

"Each of you can swing an entire precinct for Hillary if you vote," Obama told supporters in North Carolina Thursday. "Or you can swing it for her if you don't vote. Your vote matters."

Obama will be back in North Carolina Friday in hopes of encouraging turnout before Saturday, the last day of early voting in that state.

He returns to Florida for an early voting rally Sunday, when many African-American churches will be organizing Souls-to-the-Polls drives.

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