I'm sympathetic to Santorum but the ad looks way out of line, and is not convincing. You're right - it's hard to convey in 30 seconds. I think he failed, but wait and see.
It's also way too late in the game. It smacks of desperation.
How about this one...has this already been posted? Check out the Wiretap spot.
http://www.citizensunited.org/news/Read.aspx?ID=37