October surprises still have the power to rock presidential campaigns — just ask FBI Director James Comey — but the impact of last-minute bombshells isn’t quite what it used to be, thanks to the most important recent technical trend in politics: early voting.

By the time Comey released his cryptic and controversial Friday announcement that the bureau would be parsing a new batch of emails — reportedly among thousands found on devices belonging to Anthony Weiner — approximately a quarter of voters, a lot of them Hillary Clinton supporters, had already cast ballots through in-person and absentee balloting.


But that doesn’t mean the FBI director’s letter can’t shake up the race — which had been tightening from a 5-to-7 point Clinton advantage to a 2-to-4 lead pre-Comey — and the dynamic, in the words of one Trump adviser I talked to, is now “better for us.”

The adviser added: “Not a knockout blow, but we’ve got new life if we can keep it front and center for the next eight days.”

In the past few days, the Clinton campaign has a new worry: dampened enthusiasm, especially among African-American voters, who have been underperforming their early-vote totals in critical states like Florida, North Carolina and Virginia.

In other words, we are at a moment of maximum uncertainty in a race everyone thought Clinton, the shakiest of late-game closers, had wrapped up a week ago.

That’s why I thought it was logical — to go Vulcan at a nervous-breakdown time — to offer a wide-ranging explainer on what the campaigns themselves are actually focusing on as they scramble to get their people to the polls: the mechanisms of early voting and the hidden, high-tech and cash-intensive effort to get voters to the polls through targeting before and on Election Day.

To answer some of the questions, “Off Message” tapped two of the most experienced data, analytics and turnout specialists in either party last week for a hasty symposium: Mark Stephenson of Red Oak Strategic, a veteran of GOP presidential campaigns who works on congressional races, and John Hagner of Clarity Campaign, who has worked for dozens of House and Senate races over the past couple of cycles for the Democratic Senate and House campaign committees.

“What we’re showing is there’s not a lot of voters that are in play. We're looking at maybe 6 to 7 percent of the population that hasn’t completely rejected voting for the other party, and most of them have a strong opinion about who they'll vote for,” said Hagner, speaking on Friday, minutes after Comey’s letter to Congress became public.

“I think the biggest piece is going to be turnout effect,” Hagner continued, meaning it could dampen enthusiasm for Clinton backers and spike turnout for Trump’s team.

Stephenson agreed but also thought the news could have a more explosive and unpredictable effect by flipping voters. “You have a large percentage who will or would have voted over the next nine days,” Stephenson told me during the hourlong sit-down. “It remains to be seen what impact that will have, what might happen from Trump, and what — that’s a big unknown — about what will happen over the next week. So, those could have shifts in the data.”

Clinton is helped — but not insulated — by some Democrat-friendly trends gleaned from the blizzard of early-voting data blasted out by state election boards.

In general, early voting in states like North Carolina, Nevada, Ohio and Colorado tends to favor Democrats, who have a harder time getting their voters, however committed they might be to Hillary Clinton, to the polls. Absentee balloting, traditionally, helps the GOP — absentee voters tend to skew older and also include members of the military, who are mostly male, right-of-center voters.

“Democrats like to expand early voting because we rely more on get-out-the-vote and on turnout of unlikely voters, and with early voting we get three weeks to try to get people to vote instead of one day,” Hagner explained, which is why Clinton has invested so much in data and field offices. “It gives us a lot more time to get out there and call folks and knock on their doors and get them to the polls.”

The preliminary results, tallied before the Comey bombshell, show that the effort — led by Clinton’s field organizer-campaign manager Robby Mook — seems to be paying dividends. The Democratic nominee is holding an approximately 15-point lead in early balloting, according to a Reuters/Ipsos analysis of state data and other reporting released on Sunday. It doesn’t represent a firewall, but every bit helps — and Clinton’s early strength in North Carolina might prove to be a major factor in the election’s outcome if Trump surges through the tape of Nov. 8.

Although there have been signs African-American voters are lagging behind 2012 rates, Democrats, as of this past weekend, had cast 43 percent of the early ballots to Republicans’ 31 percent in North Carolina. In total, the number of Democratic ballots is lagging tallies from four years ago, but that is largely the result of the GOP-controlled state legislature’s decision to scale back polling sites. In a heartening sign for Clinton, 56 percent of the votes cast in the Tarheel State have come from women — a possible sign of a backlash against Trump, who bragged about sexually harassing women over the years in a 2005 hot-mic tape.

Florida, where polls showed Trump surging ahead of the Comey announcement, is more of a jump ball. But there are positive data points for Clinton there, as well, with Hispanic early voting nearly double the pace of 2012. Democratic field experts, like Steve Schale, are predicting a 2000-type photo finish (despite a couple of recent polls showing Trump with a slim but sturdy lead). But the biggest Florida takeaway might be the start of an anti-Trump wave among Latino voters, who, in the words of Trump-philic ex-Arizona Gov. Jan Brewer, “don’t vote.”

In Brewer’s home state, where two-thirds of voters cast ballots before Election Day in 2012, Democrats have been assiduously combing the absentee voter file to encourage their supporters, many of them Hispanic, to vote early. According to data released last week, Republicans maintain a slim advantage of about 38,000 ballots — but that’s less than half the lead they had four years ago. In Nevada, which had a 70 percent early-voting rate in 2012, Hispanic participation is up significantly.

“There’s actually a lot of evidence that the Clinton campaign is doing it really well, bringing new people into the process,” said Hagner. “I think the Clinton campaign really is focused like a laser beam on that, unlikely voters, bringing new people in. You know, they’ll put the vote early for everyone because it’s nice to get them off their walk lists and call lists, but they’re focused on Latino voters and they’re focused on unlikely voters. It’s data-intensive, organization-intensive, and they've invested in it.”

Hagner pointed to signs that in North Carolina, tens of thousands of Democrats who didn’t vote in 2012 were voting early this time around, eclipsing their Republican counterparts. “So, there is some evidence that Democrats are doing a pretty good job,” he said.

Yet even before the Comey revelations, the picture was muddy. About two-thirds of independents, as any decent Democratic operative will tell you, are really Republicans so pissed off at party labels they won’t wear the uniform. And what makes the early-voting data so opaque this time around is that an increasing number of indies are participating.

“One thing we've seen has been a trend this year of more and more independents voting early, at least, even more so than in 2012 and 2014,” said Stephenson, reading off his ever-open laptop.

“In states like North Carolina and some others, you have more and folks who are independent voters, registered independents, who have decided to take part and vote early,” he added. “So, any campaign that’s organized and can target ... Trump supporter[s], and target them to vote early, yes, they could take advantage of that, of course, especially because you already have sort of a trend of those — that larger pool of people voting absentee and voting early. But in absentee and early vote, one of the biggest things that you need to have is organization, and these things also cost a lot of money.”

And that’s where Clinton, a plodder and a planner who has built the most impressive state operations in history, has a distinct — if tough to quantify — advantage over Trump, who only recently began focusing resources on ground operations, largely through the Republican National Committee. He has access to a rich database of supporters, but doesn’t have the troops to use the data to get them out to the polls, Republican operatives say.

Here’s why resources count: Campaigns compile extensive “voter files” on people who are likely to vote for their candidate. Using a variety of data (previous voting patterns, location, magazine subscriptions, consumer purchases, etc.), voters are given two main scores — on, say, a simple 1-to-100-point scale — that measure the likelihood they’ll support a candidate and the likelihood they’ll actually take the time to vote.

Big TV ad buys, debates and Trump rallies are designed to woo voters; get-out-the-vote operations, like Clinton’s, are built to get “low propensity” supporters to turn out.

“The best way to change someone's behavior, though, is to have folks who look like them, who understand them, to talk about why the election's important, more than why Hillary is the right candidate,” Hagner noted. “That’s what the field — the Democratic field efforts tend to focus on those people, where we get folks going door-to-door and calling to say, ‘Hey, I live here. This is important to me. ... We’re going to go vote early on Tuesday. You should come with us.’”

The more cash and volunteers a candidate has, the greater number of voters his or her campaign can afford to target. That means Clinton can target not only supporters with a 70 percent or 80 percent chance of voting for her, but also backers with lower “propensity” or “preference” scores. Trump simply can’t match that effort, so he needs to generate more enthusiasm than Clinton does, which helps explain why he relies so heavily on public appearances.

That’s why the Comey investigation is so important to him: It’s a deus ex machina that plays to all his advantages. He’s hoping it will dampen enthusiasm among Clinton’s supporters and motivate his own people to help him overcome Clinton’s organizational advantages.

And it even gives him a hedge against her gains in early voting: Two critical states, New Hampshire and Pennsylvania, don’t have any in-person early voting and make it difficult to file absentee ballots, so almost all of the voters in those states will be exposed to a week of all Comey, all the time.

“You do see some places where, from both sides, there may be some enthusiasm lacking, where maybe the turnout ends up being lower than we think it is,” said Stephenson. “That’s why the [email controversy] might have an impact on the results. ... You have a large percentage who will or would have voted over the next nine days, 10 days. ... It’s a big unknown, about what will happen over the next week. We could have shifts in the data.”