NPR explains.

Thousands of North Carolina residents answered their telephones last week to hear this message, delivered in a deep, soothing voice:

“Hello. This is Lamont Williams. In the next few days, you will receive a voter registration packet in the mail. All you need to do is fill it out, sign it, date and return the application. Then you will be able to vote and make your voice heard. Please return your registration form when it arrives. Thank you.”

In fact, the deadline to register for the May 6 Democratic presidential primary had already passed. The robocall went to many registered voters who were expecting to vote that day. The call and follow-up mailings left many wondering whether they were registered for the primary or not.

This sounds like a classic example of voter suppression — sowing confusion in order to drive down turn-out. The calls seemed to be aimed at African-American communities, places where Illinois Sen. Barack Obama is expected to run well ahead of New York Sen. Hillary Clinton.