They will print your message inside of the cards (look at the website).
Try this one on for size and send it to your liberal friends/relatives/the press:
"YOU could have been aborted and YOU wouldn't have had any CHOICE about it."
You could submit the greeting to PP (yes you would have to fund them a little but you would have the joy of sharing your message with at least one person there) OR you could create your own cards at any print shop or even on your computer.