COLUMBUS, Ohio — Donald Trump and his campaign surrogates have been banking that a cadre of voters who rarely surface at the polls will show up and buoy his campaign as it drives toward Tuesday's election.

But while reliably Republican voters are showing up at early-voting sites, they are being met there by a countering army: women, Latinos and other supporters of Hillary Clinton.

The early vote is an imperfect measure of electoral results, but two points seem clear after weeks of voting in some states.

The first is that an election whose negativity seemed destined to drive away more voters than it attracted has so far done the reverse, prompting a record deluge of early voting in many of the states that will decide the presidency. By Tuesday, experts estimate, as many as 40 percent of the eventual ballots may have already been cast.

In Maryland, about 860,000 votes were cast during the early-voting period, amounting to about a fifth of all registered voters.

The second is that Trump has been helpful to Clinton's long efforts to increase voting among women and Latinos.

In key states like North Carolina, Nevada and Florida, gains among women and minority voters have bolstered the Democrat's efforts to block Trump's avenues to victory. Trump, too, has seen big turnout increases among his targeted voters, but they have not overwhelmed the Democratic forces, as some in his party had hoped.

Along with support for Clinton, the intensity is driven by distaste for Trump, who has made high-profile derogatory comments about women and Latinos throughout the campaign.

Early voters are valued by both campaigns, and particularly so in this scandal-tossed year; once cast, the verdict cannot be changed if the voter's sentiment shifts, except in rare cases unlikely to change the election's outcome. And they are also protection, particularly in the Midwest and the North, against an outbreak of weather that might complicate efforts to get to the polls on Election Day.

There is no certain connection between the early-vote winners and ultimate election results. Until Election Day, it will be impossible to assess whether those who cast ballots early are the same ones who otherwise would have shown up on Tuesday or whether they significantly expanded the pool of voters. At least one key state, Pennsylvania, has little early voting, meaning that its results will rest on Tuesday's turnout.

Clinton officials said in a conference call Friday that they had targeted in their early-voting efforts those who don't always show up, so that they would broaden their overall number of voters.

“Our strategy all along was ... to bank the voters who have the lowest propensity to turn out,” Clinton campaign manager Robby Mook said.

Locking those voters down also helped free Clinton to concentrate in the final days of the race on places where the majority of votes are cast on Election Day. She was in Detroit and Pittsburgh on Friday and will be in New Hampshire and Philadelphia in coming days.

Trump campaigned in New Hampshire and Pennsylvania on Friday, emphasizing his contention that Clinton should be disqualified from the presidency due to corruption.

As he has in recent days, he also encouraged early voting.

Those studying the numbers say there has been an uptick in voters who rarely cast ballots or who never have. The latter category is particularly valuable to Clinton, since younger voters side with her by a large margin.

Mook, in his conference call, portrayed the Democratic effort as a blazing success and took to task the decidedly lower-profile effort by Trump to draw out early voters.

“We have so far not seen a surge from the Trump camp and his voters,” Mook said. “And if he hasn't banked his votes by this point, he's going to have an even taller task.”

But if Democrats are bragging about an advantage, the numbers paint a more nuanced picture: Voting is up among many groups, including those who would be reliably considered Trump voters.

Looking at the vote in North Carolina, for example, University of Florida political scientist Michael McDonald said that the women's vote had increased 11.8 percent over the 2012 totals. That would aid Clinton, based on her fairly strong standing among women.

Yet the men's vote had increased by 10.4 percent, McDonald said. That would accrue to Trump.

Both candidates have tried to boost early voting in the last several weeks. Clinton arrived in Ohio the day before the close of registration in mid-October, and two days before the start of early voting, a travel pattern she has kept up in other states.

Ohio remains one of the campaign's biggest challenges; although Democrats were catching up in early votes as the final weekend before the election neared, Republicans had outdistanced them early on.

The question for those studying the early vote is what proportion of the votes of different subgroups is aligning with either candidate. Clinton has made a big pitch for the support of Republican women living in the suburbs of the key states, a vote that usually goes to the GOP nominee. Until the Election Day ballots are counted, it won't be known how successful her efforts have been.

Similarly, a boost in Democratic early voters would be a strong sign for any other party nominee. But this year, Trump has attracted the votes of blue-collar Democrats, particularly in the Midwest, so he too could benefit from a surge in the opposite party.

In any case, by the time the polls close Tuesday, many more voters may have cast ballots than anyone might have predicted.

“There's been this theory that since the election has been so overwhelmingly negative that would depress turnout,” said Tom Bonier, CEO of TargetSmart, which analyzes voter data.

“The early-vote data suggests so far that's not the case, that we are headed toward a high-turnout election.”