As the presidential race heads into its final weekend, Donald Trump is showing strength in Iowa and Ohio pre-Election Day voting, while Hillary Clinton’s advantage in early balloting looks stronger in North Carolina and Nevada, an analysis showed.

Democrats and Republicans in Florida, the biggest swing state, have returned ballots in nearly even proportions. There have been about 2.9 million votes cast there so far, exceeding the level recorded during the entire early voting period four years ago and with one final weekend of balloting remaining.

Early, in-person voting is nearly complete in many of the battlegrounds states. It ends Friday in Nevada, this weekend in North Carolina, Ohio and Florida, and on Monday in Iowa. Those states, among the main targets for Trump and Clinton, have a total of 74 of the 270 Electoral College votes needed to win the presidency. Trump needs to win at least four of those states to have a realistic path to victory.

Clinton, in particular, is putting heavy emphasis on early voting, as she seeks to mimic the success of President Obama’s winning 2008 and 2012 campaigns. Republicans have historically shown up in greater numbers on Election Day, and early votes by Democrats can counteract that advantage.

Nationally, more than 37.5 million votes have already been cast, either by mail or in person, said Michael McDonald, a University of Florida professor who runs the U.S. Elections Project, which updates the statistics daily. As much as 40 percent of this year’s vote is expected to be cast before the election.

The Clinton campaign was trumpeting the early voting numbers, saying they are a “firewall” against Trump. Campaign manager Robby Mook told reporters on a conference call Friday that the Republican is falling behind. “If he hasn’t banked his base by this point, he’s going to have an even taller task in these last few days,” Mook said.

In Nevada, Mook said Clinton’s campaign estimates that more than 40 percent of registered voters have already cast ballots and that Latinos there and in other battlegrounds are “turning out at dramatically higher rates than in 2012.”

Pointing to Nevada, North Carolina and Florida, Mook said Democratic early voters have placed Trump in a position less favorable than the one 2012 Republican nominee Mitt Romney faced on Election Day.

Based on his analysis of the early vote and polling in Nevada and Colorado, McDonald said those two states “look solid for Clinton at this point,” while he expects Florida, North Carolina and Ohio will be much closer.

Trump has slim advantages in North Carolina, Iowa and Ohio, according to RealClearPolitics poll averages, while Clinton has a slim edge in Florida. In Ohio, the number of early ballots requested and returned has lagged what they were at the same point in 2012 statewide and in key counties.

While election-law changes in some states can make comparing numbers this year with 2012 problematic, that isn’t the case in Iowa, where Republicans are closer to being on their pace of four years ago than Democrats.

Republicans in Iowa had cast 174,452 ballots through Wednesday, while Democrats had completed 217,054, according to data from the secretary of state’s office. Both parties are trailing their pace of four years ago, although more so in the case of the Democrats. Republicans have returned 96.9 percent as many ballots when compared to 2012, while Democrats have only completed 89.8 percent.

The proportion of early votes returned by people registered as independent or nonpartisan is harder to use for election forecasting. In Iowa, that group has returned 110,975 ballots, down from 135,547 at this point in 2012.

In North Carolina, registered Democrats account for almost 43 percent of the 2.3 million early votes cast as of Wednesday, compared with 32 percent for Republicans and 25 percent for unaffiliated voters.

But Democrats are running behind the number of early ballots cast at the same point in the 2012 election — in which Obama lost the state to Romney by 2 percentage points — while Republicans are running 13 percent ahead.