The New York Times offers this report, which discusses this new report from the Brennan Center.

UPDATE:  Ben Smith offers some sensible caveats to the Brennan Center report, and concludes with the following: “And so another way to look at the study is that in the presidential election, ID laws in Wisconsin and laws restricting registration and early voting in Florida and Ohio will likely help the Republican nominee, at least on the margins. Laws making it harder for felons to regain the franchise in Florida and Iowa may have the same effect.”