Voting in the presidential election begins in September, giving Republican Donald Trump less time to turn things around than supporters might assume.

Election Day is Nov. 8 — a full 88 days away. But absentee voting begins in September in at least half-dozen swing states that could decide the White House race.

In North Carolina, a crucial battleground, where Trump and Democrat Hillary Clinton are running even, absentee ballots are to be mailed to voters on Sept. 9. That's less than a month from now.

In Ohio, a bellwether for Republican presidential candidates, absentee and in-person early voting begins in nine weeks — on Oct. 12 — and runs through Election Day.

The accelerated voting schedule affords Trump even less time to reverse course and change minds than appears on the already shrinking, formal electoral calendar.

This could spell trouble for the Republican nominee given Clinton's organizational advantage and massive head start in paid advertising.

Mining early and absentee votes is all about proficiency in field and data, and team Clinton is more built out and advanced in those departments than Trump — even considering the technological support his campaign is receiving from the Republican National Committee.

There's also the issue of whether Trump's late start in paid advertising, presumably coming later this month or early next month, will come too late to convert persuadable voters.

"We no longer have an Election Day, we have an Election Month," Nathan Gonzales, editor and publisher of the nonpartisan Rothenberg & Gonzales Political Report, said Wednesday. "That makes it harder for campaigns to peak at the right time but it rewards campaigns that are well-organized."

Since the political conventions, Clinton has jumped out to a national lead of about 8 points over Trump, while also expanding her margin in key battleground states like Colorado, Ohio and Pennsylvania.

Clinton's lead is hardly insurmountable.

There have been swings in the race previously. Trump led in early May, only to fall behind until just after the Republican convention, when he briefly caught Clinton before falling behind again after the Democratic convention.

But if Clinton is still leading in September when absentee ballots begin hitting mailboxes, she'll begin to bank votes that will be lost to Trump no matter what happens in the final stretch of the campaign, which includes the three presidential debates and single vice presidential faceoff.

The Democrats have traditionally outperformed Republicans in absentee and early voting. That was the case four years ago.

But Republicans, specifically the RNC's revamped turnout program that the Trump campaign is relying on for much of its data and field operations, have made improvements and now focus intently on voters that prefer to vote early and absentee.

Like the Democrats, the RNC also uses advanced analytics to target low propensity voters inclined to vote Republican, if they would just turn out, and targets this cohort throughout the absentee and early-voting period.

The GOP's gains on this front were measurable and significant in the 2014 midterm elections, especially in Iowa where Democrats had long blown the Republicans out of the water. There, Republicans kept pace, and it believe it was a factor in Joni Ernst's victory in the Senate race.

"The investment we've made since 2014, in terms of our predictive modeling program, puts us in a good position," an RNC official said. "We've been pushing absentee balloting in the field for months."

The Clinton campaign might still have an edge.

The Democrat's ground game is run completely in-house, and has been deployed in the states for months. Trump has a skeleton crew by comparison, got a late start. True, the RNC has been prepping for more than a year, but has been slower to ramp up than originally planned.

Additionally, Clinton's operation was road-tested during her tough primary campaign against Sen. Bernie Sanders of Vermont. And, the former secretary of state should be able to build on the groundbreaking advances President Obama's campaign employed to turn out voters in 2008 and 2012.

"From the first day that we put organizers in battleground states we've mapped out plans that take advantage of all available tools to ensure more voters have their voices heard in this election," Clinton campaign spokeswoman Lily Adams said. "As we have learned in past election cycles, these are critical ways to expand the electorate."

The first absentee ballots are to be mailed out in North Carolina on Sept. 9. Other battlegrounds mailing out absentee ballots next month are Pennsylvania (Sept. 19); Florida and Michigan (Sept. 24); Missouri (Sept. 27); Iowa (Sept. 29) and New Hampshire (late September to early October.)

Not all of those states will necessarily be contested. The Washington Examiner confirmed the information with elections officials in each state.

In Colorado, all voting is now conducted by mail; ballots are mailed to all registered voters beginning on Oct. 17. Ohio, perhaps most crucial of all to Trump's hopes, begins both early and absentee voting on Oct. 12.

That gives both campaigns nearly four weeks to boost their turnout by hounding voters and dragging them to the polls.

In 2012, President Obama's campaign used a summer advertising blitz to demonize Romney and then took advantage of Ohio's calendar and deployed a more developed ground game to scoop up the voters it created, eventually besting Republican nominee Mitt Romney by 3 points.

Clinton is looking to do the same to Trump, who on Wednesday said during a campaign rally that he was holding back from investing in paid advertising for the time being.

"We haven't spent anything yet, but we will be. We haven't spent anything yet, we're holding it," he said.