|Absentee ballots requested by Iowa voters as of November 5, 2012
Absentee ballots received by Iowa county auditors as of November 5, 2012
As of yesterday, Iowa county auditors had received more than 673,000 completed absentee ballots. That's not the final early voting number, because some mailed ballots will continue to arrive, and they will be counted as long as they were postmarked by November 5. Also, Iowans may hand-deliver completed absentee ballots to their county auditor's office today until polls close at 9 pm.
Democrats lead Republicans by more than 65,000 in returned ballots. I consider it likely that Obama leads among the no-party early vote too, so Romney probably has to make up a deficit of between 70,000 and 90,000 votes among election-day voters.
Since 1,528,715 Iowans voted in the 2008 general election, and 1,497,741 Iowans voted in the 2004 general election, I assume that at most 1.6 million Iowans will cast ballots in this year's election (my best guess would be total turnout closer to the 2008 level).
Former Bush/Cheney campaign staffer Adrian Gray has predicted that Republicans would be able to make up a 60,000 vote deficit on election day in Iowa. He sees Romney on the edge, needing to win today's vote by 7 points, as George W. Bush did in 2004. I don't see how he arrives at that number.
With nearly 700,000 votes already banked, somewhere between 800,000 and 900,000 Iowans will cast ballots today.
If 850,000 Iowans vote today, Romney would need around 55 percent of them to make up the early vote deficit, depending on how much the early no-party vote tilted to Obama.