A mistake that went to every single voter in the state?

Well, not quite. But the reality is bad enough. The card was send to 1 million eligible voters in Maryland, according to Ross Goldstein, deputy administrator of the Maryland Board of Elections. The state has 3.5 million registered voters, he said. Census data shows the state had 5.9 million residents in 2011.

"I don't think it will impact turnout on the Election day," Goldstein said, though he acknowledged the postcards have confused some people who are already registered. "Many people who erroneously got a notice have called."
The cards were sent out as part of an initiative between state election officials and the Pew Center on the States to help update the voter rolls by cross-checking them with other databases.