PRINCETON, NJ -- Fifteen percent of registered voters nationwide have already cast their ballots in this year's election, according to Gallup Daily tracking for the week ending Oct. 28. That is up sharply from 5% a week earlier. The overall percentage either having already voted or planning to vote before Election Day has also increased -- to 33%, from roughly 25% in each of the prior three weeks.

Americans' self-reported plans for when they will vote are similar to what they were at roughly the same point in 2008. Gallup polling conducted Oct. 24-26, 2008, found 17% of registered voters saying they had already voted and 16% still intending to vote before Election Day, totaling 33%. By the end of the campaign, in Oct. 31-Nov. 2 Gallup tracking, 27% reported they had already voted and an additional 5% intended to vote early -- totaling 32%.

The percentage of likely voters who have either already voted or plan to vote early is now 36% -- indicating that this will probably be the percentage of early voters in the actual electorate.

2012 Early Voters Are Older, Concentrated in the West

Early voting this election year is most prevalent in the West, followed by the South and the Midwest, but is relatively light in the East. These differences largely reflect regional differences in state laws on absentee and mail voting, with two states -- Washington and Oregon -- focused exclusively or mainly on mail-in voting. One in four voters in the West say they have already voted, and another 30% plan to vote before Election Day. The combined 55% in the West contrasts with 40% in the South, 23% in the Midwest, and 9% in the East.

Early voting is also strongly related to age, with seniors the most likely to have already voted (26%), compared with 7% of voters aged 18 to 29.

Postgraduates are more likely than voters with no more than an undergraduate-level education to say they have voted or plan to vote early, while adults with no college experience are the least likely.

Gallup finds little difference in early voting by gender, race, or household income.

These demographic differences in early voting are consistent with what Gallup found in the 2004 and 2008 elections.

Political Impact of Early Voting Looks Minimal

By 19% to 15%, a slightly higher percentage of Republicans than Democrats have already voted. When those who intend to vote before Election Day are factored in, the gap is similar: 37% of Republicans vs. 33% of Democrats.

However, when one looks at the voting intentions of likely voters according to candidate support, the political impact for the two candidates appears to be roughly equal. Of Barack Obama's supporters, 15% have already voted and a total of 33% indicate they will vote early. Of Mitt Romney's supporters, the figures are 17% and 34%, respectively.

Romney Leads Among Early Voters, Similar to His Likely Voter Lead

Thus far, early voters do not seem to be swaying the election toward either candidate.

Romney currently leads Obama 52% to 46% among voters who say they have already cast their ballots. However, that is comparable to Romney's 51% to 46% lead among all likely voters in Gallup's Oct. 22-28 tracking polling. At the same time, the race is tied at 49% among those who have not yet voted but still intend to vote early, suggesting these voters could cause the race to tighten. However, Romney leads 51% to 45% among the much larger group of voters who plan to vote on Election Day, Nov. 6.

Bottom Line

Early voting could play a pivotal role if it results in higher turnout among a particular candidate's supporters than would otherwise be the case if everyone waited for Election Day. As a result, the presidential campaigns are urging their supporters in swing states, in particular, to lock in their vote now, lest anything interfere with their ability to turn out on Nov. 6. There are reports that Hurricane Sandy has disrupted early voting in parts of the East; but given the relatively low rate of early voting in that region, this may not have a major impact on early voting overall.

Whether the candidates' focus on early voting will ultimately pay off isn't clear. At present, early voting appears to be a convenience that older voters are using disproportionately; they may welcome the opportunity to vote by mail rather than in person on Election Day. It is also relatively common in the West and among postgraduates, groups that may have better access to information about how to navigate the early voting process. Some states not only encourage early voting, but mandate it, thus accounting for regional differences. However, despite the hype, it doesn't appear that early voting will have a major impact on the U.S. popular vote, or be much more prevalent than it was four years ago.

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