I have never considered Romney, nor Obama, to be charismatic, regardless of what the media tells me. In a debate setting, I have found Gingrich charismatic, but not for years as a political pundit on TV and radio.
As for Santorum, at times during the debates, given his very limited camera time, I found him articulate, intelligent and persuasive. Like Gingrich, I never witnessed charisma when doing his TV work. But, if he indeed carries (or has carried) that same debate posture over to his campaign speeches and town halls (of which I've never seen him in person), I don't believe that the “lack of charisma” criticism will stick. Time will tell.
Great post.