Such is the conclusion reported by “Barry Burden”:https://mywebspace.wisc.edu/bcburden/web/ and “Ken Mayer”:http://users.polisci.wisc.edu/kmayer/ in this “NY Times op-ed”:http://www.nytimes.com/2010/10/25/opinion/25mayer.html?_r=2&pagewanted=all. Here’s why:
bq. How can this be? The answer lies in the nature of voter registration laws, and the impact of early voting on mobilization efforts conducted by parties and other groups on Election Day.
bq. In most states, registration and voting take place in two separate steps. A voter must first register, sometimes a month before the election, and then return another time to cast a ballot. Early voting by itself does not eliminate this two-step requirement. For voters who missed their registration deadline, the convenience of early voting is irrelevant.
bq. Early voting also dilutes the intensity of Election Day. When a large share of votes is cast well in advance of the first Tuesday in November, campaigns begin to scale back their late efforts. The parties run fewer ads and shift workers to more competitive states. Get-out-the-vote efforts in particular become much less efficient when so many people have already voted.
They recommend combining early voting and election-day registration.