South Floridians mark their ballots during the last day of early voting in Miami Beach, Fla., Saturday, Nov. 3, 2012. (Alan Diaz/AP Photo)

This weekend marked the end of in-person early voting in the majority of key battleground states. Early voting sites remain open in the key Midwestern states of Iowa and Ohio, as well as in a handful of counties in Florida.

But the doors have closed for early in-person voters in Colorado, Nevada, Virginia, Wisconsin and most of Florida, although not without some drama in the Sunshine state.

More than 29.8 million ballots have already been cast via early and absentee voting, with the early vote expected to make up about 35 percent of the total votes cast, an increase from 2008, when 30 percent of the total vote was cast before Election Day.

The uptick in the percentage of votes cast before Election Day continues with recent trends: early voting has increased in popularity for the past two decades, as more states have begun to make the option available. But voting expert Michael McDonald notes that early voting might be a large share of the overall vote this year as a result of Superstorm Sandy.

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"It may be that early voting will, ironically, be a larger share of the overall vote even if overall turnout is down, as early voters were able to return their ballots before or after the storm in areas where there have been severe disruptions," McDonald, director of the United States Election Project, said.

Republicans and Democrats claim to be winning the early vote, and they both stand on solid ground from which to back up their assertions.

In short, Democrats have the numerical advantage in the vote count. In all but one key battleground state - Colorado - registered Democrats have cast more ballots than registered Republicans (Republicans have a slight edge in Colorado).

But Republicans have made much bigger gains in getting out the early vote since 2008 than their Democratic opponents. Take a look at the key battleground state of Nevada, for example, where early and absentee voting made up about 67 percent of the total votes cast in the state in 2008.

Democrats outperformed Republicans in early voting that year by a little less than 12 percentage points, 47.6 percent of the early votes cast came from registered Democrats, while 35.8 percent came from registered Republicans. This year, that gap has narrowed to roughly 7 points, with registered Democrats accounting for 43.9 percent of the votes cast already, and Republicans making up 37 percent, according to figures from the United States Election Project.

In Florida in 2008, registered Democrats cast 44.9 percent of the early votes, while registered Republicans only cast 37.9 percent. This year, that gap is down as well. Registered Democrats have accounted for 42.6 percent of the early vote, registered Republicans 39.5 percent.

Across the board, in 2008, Democrats held an 11 percentage point advantage over Republicans going into Election Day in the battleground states where party registration was available, but this year, that gap has been cut down to about a6 point advantage, according to one GOP official.

One of the reasons for Republican gains in early voting has to do with an improved get-out-the-vote operation (commonly referred to as "GOTV") from 2008. In 2008, Republicans had a weaker operation than Democrats. This year, Republicans amped up their game, targeting "low-propensity" voters, or people who, when they vote, vote Republican, but have not consistently turned out in elections.

"If you live in Ohio and Iowa, for example, and you're a low-propensity Republican voter, you voted in a primary or you're registered Republicans but you've missed some, what you're going to get form the Romney campaign and the RNC is somebody coming to your door with an absentee ballot, you're going to get mail that has absentee-ballot request forms," Republican National Committee spokesman Tim Miller said.

"The number of contacts that you'll have from volunteers and mail and phone calls … during the early vote and absentee period was going to be substantially more than if you are somebody who votes every day, every election."

Republicans hope that this strategy, banking those maybe but not-certain voters early, will ultimately yield a victory Election Night.

From a simple mathematical standpoint, however, Democrats are ahead in the vote count in four out of the five battleground states that offer in-person early voting and register voters by a political party: Nevada, Iowa, Florida and North Carolina.

The key Midwestern states that permit in-person early voting - Ohio, Iowa and Wisconsin - do not register by party affiliation, so it is impossible to make any definitive statement about which party is ahead in the vote count. Those three states have been identified as a kind of Electoral College firewall for Obama that offers him a path to 270 electoral votes even if he loses in all of the other battleground states

The take-away from these early vote numbers at the end of the day points to the same point analysts, pollsters and both campaigns have been saying all along: The race is tight and the outcome, whatever it is, will likely be very close.