Early voting is already underway in Iowa and analyst in and out of the state are trying to get a sense of how the vote is breaking and which side has banked the most votes so far. So far, 52% of absentee ballot requests have come from Democrats and only 27% from Republicans. Back in 2012 Democrats held a bigger lead, 66% to 12% and saw Obama win the state 52% to 46%. Clearly Republicans are doing a better job but they are going to need to do a bit better seeing how bad they got beat in 2012.
The main question is who is early voting? Are these safe Democrat and Republican voters or are these Independents and undecided voters? If these are safe Democrat votes this is still a positive for Democrats because it has been well documented that Democrats are terrible at showing up to the polls on election day even though they have a better ground game in most states.