Alex Street at The Monkey Cage:

Some scholars argue that requiring early registration hurts voter mobilization in the final days of the campaign, when interest in the election is most intense. But skeptics counter that most of the people who fail to register in time have little real interest in voting.

Our new research shows that there is a lot of last-minute interest. We estimate that keeping registration open through Election Day in 2012 would have allowed an additional 3 million to 4 million Americans to register and vote.

We used the number of Google searches for “register to vote” in the weeks leading up to the 2012 election to measure late interest in registering. These search terms were entered millions of times, and much of the activity fell at the very end of the campaign period.