Nearly a quarter of registered voters in Iowa have voted early, despite a shortened period of time to cast such ballots.

The Iowa Secretary of State's office reported Monday that election officials received 497,085 absentee ballots from voters — 4.5 percent more than the total received in the previous midterm election, in 2014. Absentee ballots can be counted if they're postmarked by the day before an election and received by a county auditor within a week after Election Day.

By Monday, 215,663 absentee ballots had been received from registered Democrats, 13 percent more than their total for 2014. The Secretary of State's office reported 175,954 absentee ballots had been received from Republicans by Monday, 3 percent fewer than their 2014 total, and 102,893 had been received from political independents, 1 percent more than their 2014 total.

Absentee ballots can be sent in by mail, dropped off at auditors' offices in person or cast at satellite voting sites. This year, Iowa shortened the early voting period from 40 to 29 days.

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