The election of 2012 is well under way though Election Day is still more than a month away.
Democrats have the absentee ballot lead in Iowa, with voters already returning 8,800 ballots to Republicans' 2,600 as of Friday.
However, Republicans have a voter registration advantage and say they'll have a strong turnout on Election Day.
Early voting began Thursday.
Republicans took the voter registration lead in April, in part due to the 2010 primary for governor and the January caucuses that drew record GOP participation.
Part of the change also is due to a standard cleanup of voter registration rolls that involved confirming current addresses of voters by mailing notices.
The state had 89,000 fewer active voters in August than in January.