Democrats entered the fall campaign with an army of paid staffers close to five times the size of Republicans’ according to an NBC News analysis of Federal Election Commission filings.

At the end of August, the most recent date for which data is available, Democrats employed at least 4,200 people working to elect Hillary Clinton, with about 800 at the Clinton campaign, 400 at the Democratic National Committee, and nearly 3,000 on the payrolls of state parties in 13 battleground states, which typically employ a majority of field organizers.

Republicans, meanwhile, employed about 880 people during the same period, with about 130 at the Donald Trump campaign, another 270 at the Republican National Committee, and roughly 480 at the 13 state parties.

Democrats typically have the edge in field operations, which can play a pivotal role in tight races, and the disparity is not dissimilar to 2012. “In states where this is won on the margins, it really is a turnout game,” Clinton campaign manager Robby Mook said Thursday on a conference call to tout the campaign’s ground game, though they have released far fewer details about it than the GOP.

Republicans have vowed to improve over the last election’s poorly reviewed get-out-the-vote effort, a goal which proved more difficult after the Trump campaign showed little interest in building out its own ground operation to supplement the party.

Republicans say they’re still well positioned, thanks to thousands of specially trained volunteers and a head start in deploying national field staffers back in 2013, long before Democrats. “We're 33 days away, and our ground game is running full steam ahead,” said RNC Political Director Chris Carr on a separate conference call Thursday.

"The RNC has been on the ground in key battle ground states since 2013," RNC national spokesperson Lindsay Walters said in a statement. "We had a 1000 day head start on the Clinton Campaign and the DNC in engaging with voters, building relationships and creating a volunteer army. It’s the Clinton Campaign that is playing catch up."

Unlike fundraising hauls or TV ad spending, the public has little independently verifiable information about campaign’s ground operations, and none in real-time.

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NBC News extracted payroll data from the most recent FEC filings of both presidential campaigns, both national party committees, and the Democratic and Republican parties in 13 battleground states.

Still, that method has limitations. FEC reports come only out 20 days after the end of each month, so they’re dated by the time they’re released, and both sides say they’ve expanded their teams since the last reports. And the data does not specify what staffers do, so the tally includes people not involved in field organizing efforts. The tally also does not reflect the activities of allied outside organizations, such as labor unions, political action committees and interest groups.

Nonetheless, the result is the most comprehensive and verifiable picture available of the relative strength of each party’s ground game.

The Republican National Committee, which has taken up the slack for Trump, announced the addition of 392 field staffers in early September for a total payroll of 1,014 -- and a spokesman said subsequent hires have now boosted that total to 1,065 -- though those numbers won’t appear until their next FEC report and still fall short of Democrats’ operation.

Sensitive to criticism of its organizing efforts, the RNC has taken pains to highlight the growth of their ground operation.

“The RNC’s ground game is far ahead of a Clinton ground game that amounts to a cubicle factory,” chief strategist Sean Spicer said in a memo to reporters last month, adding that “the media has fallen for the Clinton camp’s false narrative that equates having a lot of campaign offices with having a superior field organization.”

The memo, which accused the Clinton campaign of playing “sleight of hand,” lumped together staffers on the GOP’s payroll with trained volunteers to claim nearly 4,000 organizers in thirteen battleground states and a total of 6,000 in 33 states nationwide. The number of paid staffers alone, however, is far lower, even by updated numbers confirmed by the committee.

The RNC is quick to point out that its “trained organizers” often fill roles similar to those occupied by paid operatives. The Clinton campaign also says it has many volunteers, although it has not released detailed figures.

Mitch Stewart, who ran the battleground states program for Obama in 2012, argues that volunteers are not replacements for staff, saying the roughly 10,000 top-tier volunteers Obama’s campaign recruited four years ago depended on paid organizers to function. And he said the RNC's recent hires come too late.

“It's just too late to build a massive volunteer effort,” he said. “The later you hire staff, the less impact you're going to see on the number of votes they can get.”

The significant difference between the Clinton and Trump sides this year is reflected in the each party’s presence in key battleground states.

As of the end of August, Democrats had more than five times the number of staffers than Republicans did on the payrolls of their respective state parties in Florida (about 520 to around 100), more than three times as many in Ohio (about 360 to roughly 90), and roughly ten times as many in Virginia (approximately 270 to 30), Pennsylvania (roughly 450 to 40) and North Carolina (300 to 20).

With the GOP’s new infusion of staff, they’ve cut that disparity to roughly 2-to-1 in Florida, Ohio, and North Carolina, though the gap remains wider in Colorado, Nevada, Pennsylvania, Iowa, Michigan, and Virginia.

Meanwhile, in New Hampshire, Republicans appear to be employing roughly 400 paid canvassers, who make a small amount of money to knock on doors and engage with voters. (For our national tally, NBC News only counted the 49 New Hampshire staffers confirmed by the RNC.)

Each party runs their get-out-the-vote operations differently, though both funnel money to state party-run coordinated campaigns, which then work to elect multiple Republican or Democratic candidates in the state.

But while the RNC, rather than Trump, is calling the shots on the party’s organizing efforts, the Clinton campaign is running its own operation in coordination with the Democratic National Committee and state parties.