And Democrats have also improved their position on the voter rolls in Colorado and Florida, outpacing Republicans in the past month, according to a CNN analysis of newly released statistics.
Voters in a handful of states have already started to request, receive, and cast absentee ballots, and some states publicly disclose how many Republicans and Democrats have requested ballots. Of course, there is no guarantee that all voters will stay loyal to their party when they cast their ballot, and no results from any states will be announced until polls close on Election Day, November 8.
In North Carolina, more than 56,000 people have requested absentee ballots: 36% of them were Democrats and 35% were Republicans. Another 28% were independents, according to the North Carolina State Board of Elections.
Over 3,600 ballots already cast in North Carolina
More than 3,600 people in North Carolina have apparently they've decided that they've seen enough of the 2016 campaign and already cast their ballots. It's a tiny fraction of voters -- more than 4.5 million people participated in the Tar Heel State in the 2012 presidential election.
Democrats have returned 1,508 ballots, or 41%; Republicans 1,227 ballots, or 34%; and Independents 909 ballots, or 29%, as of Wednesday, according to the North Carolina state Board of Elections.
In Iowa, more than 91,000 voters have asked for absentee ballots, according to the secretary of state's office. In all, 57% of those voters are registered Democrats, 22% are independents and 21% are Republicans.
These are decent numbers for Clinton, but there is a significant drop-off from 2012. At this point, four years ago, more than 105,000 Democrats had requested absentee ballots. So far this year, only 51,663 Democrats have asked for ballots. The number for Republicans was almost the same both years.
Democrats add voters in Florida, Colorado
Democrats have seen their position improve in some key states when it comes to voter registration.
Shifts in registration don't necessarily indicate which party is attracting new voters, because people switch parties, move to new states, and are removed from the rolls when they die. But these statistics contextualize the political landscape and are helpful data points in the big picture of electoral analysis.
Democrats padded their existing registration edge in Florida, by adding almost 16,000 more voters to the rolls in the past month than Republicans did, according to the Florida Department of State. Their overall advantage in the state is about 274,000.
It might seem like a nearly insurmountable a lead, but it isn't. President Barack Obama had an even larger advantage in 2012, but he only carried the Sunshine State that year by about 74,000 votes.
Out west, in Colorado, Democrats have nearly erased what was once a formidable Republican registration advantage. They outpaced Republicans by about 9,000 voters in the past month, according to new data from the Colorado Secretary of State.
That means the Republican registration advantage in Colorado is only about 2,600 right now. It was nearly 12,000 in August, and it was three times that size in November 2012, when Obama carried the state.
Registration numbers have been stable in several other key swing states. That's good news for Democrats in Pennsylvania, North Carolina and Nevada, where they have the advantage. And that's good news for the GOP in New Hampshire and Iowa, where there are more Republicans on the rolls.
Currently, Democrats lead Republicans by about 919,000 registered voters in Pennsylvania, about 644,000 in North Carolina and about 71,000 in Nevada.
Republicans lead Democrats by about 34,000 registered voters in Iowa and about 24,000 in New Hampshire. The voter rolls were very stable in both states in the past month. For example, the GOP edge in Iowa grew by only 175 votes since August.