Rick Perry at St. Anselm's College in New Hampshire today:

“Those who are going to be over 21 on November 12th, I ask for your support”

Two things:

(1)  The general election is on November 6, 2012, not November 12.

(2)  Eighteen year olds can vote.

… although maybe Perry already knew that second one, and just doesn't want the vote of people under 21.