Iowa is ground zero for early voting, where more than 300,000 voters or 20 percent of the eventual electorate already cast ballots. Many have observed that registered Democrats outnumber Republicans by a 49-31 margin, giving registered Democrats an early edge of 55,000 in ballots already cast. Democrats hold a smaller 15 point lead in ballot requests, but hold a larger numeric edge of 70,000 ballots. Is this a sign that Obama is about to sweep to a decisive Iowa victory? So far, the numbers are not inconsistent with a win for either side.
Some have observed that the Democratic lead is reminiscent of '08, but it still represents a decline from 2008, when registered Democrats outnumbered registered Republicans by 93,000 votes in early voting. But what's overlooked is that today's numbers only represents a modest improvement from 2004, when registered Democrats outnumbered registered Republicans by 52,000 and ultimately lost to Bush by 10,000 votes.
Did Obama's improved early voting effort in 2008 make the difference between victory and defeat? Probably not. Between 2004 and 2008, Obama improved over Kerry's overall performance by 10 points or 155,000 voters—a far greater gap than that between the ’04 and ’08 early voting numbers in both absolute (41,000 votes) or percentage terms (6.4 percent). What does that mean? As much or more of the difference in Iowa’s election results in 2004 and 2008 came from swings among independent and election day voters, not changes in early voting. Most of the difference was because registered Democrats outnumbered registered Republicans in Iowa by 94,000 votes in 2008, while registered Republicans outnumbered Democrats by 10,000 votes in 2004. In 2012, registered Republicans again outnumber Democrats, this time by 18,000 votes.
There's no question that better Democratic early voting makes it harder on Republicans—their burden to turnout voters on Election Day is higher than Democrats. But there's no reason that registered Republicans can't still outnumber registered Democrats by the end of Election Day, at which point the race would come down to the preferences of voters, not just turnout. Democrats can be heartened by the possibility of a better than '04 performance among early voters, but it doesn't represent an insurmountable burden for the Romney campaign, at least not yet. In a state where the GOP has a voter registration advantage, a Democratic advantage doesn't preclude their ability to overtake Democrats on Election Day, especially in a year when Republican enthusiasm is generally assumed to be quite high.