In California, state officials projected that some 2.3 million voters sent in ballots during the 29-day early voting period, a total that could constitute half of the total votes cast. That means that people in the Golden State could have voted in the wake of the Iowa caucuses or Sen. Hillary Clinton's New Hampshire comeback victory or the South Carolina blowout by Sen. Barack Obama.
If nothing else, it could make for a very long night for reporters and candidates watching the results.
"Perhaps one of the most profound effects of the increased early voting in California is that the winner may not be declared on election night, with two million ballots likely to be left uncounted until tomorrow," the Wall Street Journal reported.
But California is not the only state seeing record early voting turnout. In Tennessee, more than 320,000 ballots were cast by the time early voting closed. Another 200,000 voted in Georgia. Early voting also took place in critical states like are Illinois, Arizona, New Jersey and Utah.
Although there has been much reporting about uncertainty amongst Democratic voters and people making up their minds at the last minute, many of the campaigns urged supporters to vote early in the hopes of ensuring that they get to the polls.
"The fluidity and uncertainty in the race would normally lead people to hold their ballots," Paul Gronke, who directs the Early Voting Information Center at Reed College in Portland, Ore., told the Associated Press. "What is cutting in the other direction is that the campaigns are out there mobilizing people to vote early."
Although there has been little reporting and research on how early voting changes the political landscape, the campaigns have been quick to adjust, according to Robert Stein, a political science professor at Rice University
"You basically divide the electorate into two groups, early and election, and you work early voters because you know they're more partisan, and you work election-day voters, because they're less partisan and less likely to vote," Stein told the Christian Science Monitor.
That micro-targeting of early voters appeared to pay off for Clinton in Florida.
According to surveys, nearly 25 percent of Florida Democratic primary voters said they cast their ballots early. Among those voters, Clinton garnered 50 percent, Obama won 31 percent and Edwards took 14 percent.
Among voters who said they decided in the final days before the primary and cast their ballots after the early-voting period had closed, Obama won with 37 percent to 34 percent for Clinton and a significant 24 percent for Edwards.
Pollsters have been trying to count early voters in their surveys, often asking voters whom they plan to support or already voted for during their calls, but the overall impact of people voting before Election Day remains unclear.
Still for some writers and commentators, the early voters have just become a source of irritation.
"Casting an absentee ballot so far ahead of Election Day is like picking a Super Bowl winner based on who's ahead at halftime. It's like recommending a book you've only halfway read. It's like getting married on the first date," Patt Morrison wrote on the Oakland Tribune's Web site.