Come on. The obvious purpose of the mailer is not to assail Grimes, it's to dupe people into thinkng that they are suspected of voter fraud, and better not show up at the polling place.
As close as the race is, it only needs to work a tiny percent of the time to have an effect.
It's just one example of the kind of crap that makes people hate politics and the entire system. Just once I'd like to see someone run at the Senate level purely explaining why you should vote FOR them, not against someone else. And that goes for both parties. And for God's sake, quit with the cheap intimidation tricks like this. It's anti-democratic, to say the least.