Jason Stein and Keegan Kyle

Milwaukee Journal Sentinel and USA Today Network Wisconsin

Madison — Six days out from Tuesday's election, key Democratic strongholds in the state are crushing their early voting numbers from the previous two presidential elections, with Republican counties underperforming compared to past years, a USA TODAY NETWORK-Wisconsin analysis shows.

The city of Madison has had 56% more early voter ballots returned so far than in all of 2012 — a record number — and now has 10,000 more voters registered than it did four years ago, according to data gathered from the Wisconsin Elections Commission and from the city clerk.

These early voting numbers don't necessarily guarantee a bigger turnout for Democrats in the overall election or a win for presidential candidate Hillary Clinton and Senate candidate Russ Feingold. Milwaukee's GOP suburbs — which did start their early voting later than Democratic cities this year — have narrowed the early voting gap over the past week.

But the strong early vote numbers in Madison and Milwaukee and lagging numbers in the GOP suburbs aren't good news for either GOP nominee Donald Trump or U.S. Sen. Ron Johnson.

Political scientist Barry Burden, who has studied early voting, says he believes the biggest factor in its increase is not increased Democratic enthusiasm but the expanded opportunities for early voting in large Democratic cities following a recent federal court decision.

But, "it still puts Republicans on their heels because they're going to have to make up the difference on election day," said Burden, a University of Wisconsin-Madison professor.

Together, absentee ballots in the Democratic strongholds of Milwaukee and Dane counties have nearly doubled the early vote totals in the key GOP counties of Waukesha, Washington and Ozaukee, according to figures from the Wisconsin Elections Commission. This underperforming in the GOP suburbs is all the more striking because, compared to the liberal cities, these conservative counties saw a larger share of their vote cast through absentee ballots in 2012.

The numbers appear to confirm trends seen among polling and early voting nationally: that Trump is performing poorly with college-educated Republicans such as those in the Milwaukee suburbs and that educated Democrats like those in Dane County are especially motivated to vote for Clinton or against Trump.

The Marquette University Law School poll Wednesday confirmed the lopsided turnout so far for Democrats, with Clinton leading Trump 64% to 25% and Feingold outpolling Johnson 58% to 29% among early voters.

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SPECIAL SECTION: Election coverage from the Journal Sentinel and WisconsinEYE

Here's some key figures from early voting in Wisconsin from state and local election officials:

Across Wisconsin, nearly 568,000 absentee ballots had been returned statewide so far, or about 86% of what was ultimately returned in the 2008 and 2012 presidential elections.

The city of Milwaukee was expected to exceed its 2012 early voting number of 37,500 on Wednesday, setting a new record for the city. Milwaukee is close to its 2012 voter registration figure already but still down somewhat from its 2008 figure.

Dane County has surged above previous years. The roughly 83,000 absentee ballots returned so far is about 111% of the Democratic stronghold’s average in the 2008 and 2012 presidential elections.

By comparison, the numbers in GOP strongholds of Waukesha, Ozaukee and Washington counties are not doing so well so far, hitting only 80% of their total early voting in 2008 and 2012.

That's a striking difference, because previously early voting was more popular in those three GOP counties than elsewhere in the state. While about three in every 10 WOW ballots were absentee in the 2008 and 2012 presidential elections, the ratio was about one in every five ballots elsewhere in the state and one in four in Dane County.

Waukesha County Clerk Kathleen Novack said she has received reports from city officials in her area that absentee ballots are coming in around the same mark as previous elections but she wouldn’t be surprised if the numbers lag the statewide pace.

“It doesn’t look like they’re going to significantly exceed what they had,” she said.