Who's been most hurt by gaffes?

[Ogre Mage]

I would say Romney has hurt himself more only because Santorum's candidacy was so improbable to start with.  That's in contrast to Perry, who actually came in regarded as a front-runner.  For those of us old enough to remember the late 90s and early 2000s, Santorum is not saying anything that we didn't already know about him.