American Prospect - America Goes to the Polls," the first report on 2016 election turnout based on official returns compiled by secretaries of state, was released by the U.S. Elections Project at the University of Florida and Nonprofit VOTE.
The lead finding of the authors of the study is that “Same day voter registration has proven to be the most effective and multi-faceted policy to increase voter participation across all states, regardless of voters’ ages and backgrounds.” States with same-day registration had a 7-point advantage over non-SDR states in 2016. Even more significant is that this advantage—actually anywhere from 7 points to 13 points—has been consistent from 1996, when only six states had SDR, through 2016, when SDR was in effect in 14 states and the District of Columbia; evidence from a larger and larger sample.
The top six turnout states—Minnesota (the highest, at 74.8 percent of VEP), Maine, New Hampshire, Colorado, Wisconsin, and Iowa—are all SDR states. Five of the six, excepting Minnesota, were also battleground states.