Republicans always want to stop likely Democrats from voting. They do this by passing voter ID laws making it much harder for some to vote chasing phantom voter fraud, often alleged but rarely proved. Close to the election they send out mailers to minority areas with confusing information. They do the same with phone calls. Democrats, on the othe hand try to register as many new voters as possible.
Rick Perry tried the 'confuse a voter' ruse, unfortunately he chose to try it on his own supporters.
For those who are unaware, the legal voting age is 18. Just another reason Perry is heading straight to the trash heap of Presidential candidates.