You might be better off going to his facebook pages, and posting sincere comments there, so supporters can read them and understand, and maybe have their hearts changed regarding their vote. And pass those page addresses to others you know. I have found people of FR to be very persuasive in any number of ways... I have that on my to-do list tomorrow...
http://www.facebook.com/pages/Florida-for-Rick-Santorum/326426320706426
http://www.facebook.com/RickSantorum