State election records show that voters in Wisconsin's Democratic leaning counties have been more likely to register to vote on the day they cast their ballots. But Republican-leaning areas also saw heavy same-day registrations.
The Wisconsin State Journal reported that in three recent statewide elections, one in eight ballots came from voters who registered that same day.
According to the election data, 16 percent of voters in Democratic-leaning counties statewide registered on the day of the presidential election in 2008, when President Barack Obama won Wisconsin.
In GOP-leaning areas, however, the rate of same-day registration was just 2.6 percentage points lower.
Two years later when Republican Scott Walker was elected governor, the same-day registration rate was 5.9 percentage points higher for Democratic-leaning areas.