Washington: Some 12 million US voters have already cast ballots ahead of the November 4 presidential election, according to early voting figures compiled by a Virginia-based university professor.
Michael McDonald, a political scientist with George Mason University in Fairfax, outside the US capital, said that based on stated party affiliation most of the early votes have been for Democrat Barack Obama.
McDonald, who has studied public data from several states where the information is available, said that 12.6 million citizens have already voted.
Early voting rules vary by state. In some places qualified US voters can vote in person ahead of the November 4 election, while in others mail-in ballots -- designed for voters away from home, such as soldiers posted abroad -- are accepted.
In the battleground state of Florida, for example, Democrats make up 45 percent of the early vote, against 40 percent for the Republicans.
In the swing state of Iowa 49 percent of the early ballots were cast by Democrats against 28 percent for Republicans.
In Louisiana the margin is even more pronounced: 58 percent against 29 percent.
The data however is incomplete, as several US states do not require voters to state a party affiliation.
"Keep in mind that in previous elections, the number of early votes typically ramps up as the early vote deadline approaches," McDonald wrote in the blog attached to his website, the United States Election Project.
"Early voting appears to be on track to exceed the 2004 levels," he wrote.
"The question remains if this means a greater share of the 2008 vote will be cast early, if turnout will be up overall, or -- as I suspect -- a combination of these two factors are in play," he added.
