I believe this to be true of Santorum and likely Gingrich as well.
The difference (right now) is momentum and delegates (for Santorum versus Gingrich).
As for delivery of message, I've witnessed improvement from Santorum and would anticipate more. Remembering back to 2000, Bush was very unpolished both on delivery and message. It seemed that he improved dramatically the further into the campaign he got. When seeing where Santorum is now, he is miles ahead of where Bush was.
Bottom line, I truly believe that Santorum can defeat Obama. While I completely understand your feelings regarding Gingrich, I just don't see how his continued campaign contributes to keeping Romney from the nomination, not with winner take all rules coming. I only see a continuation of splitting the conservative vote. The only exception would be if he can win some states. After the vote in the South, I'm not seeing any he could win.
I take it back a number of years further back than you. I think you are dead wrong. Rick’s problem is he has about 60% of the conservative base of the republican party. He has to have more than that to win. His other problem is that he truely excites the other side. If you can’t get all your base and you get the other side mad, then you are in real trouble. You are not going to win me over, we just disagree. I am right of course. Just joking. Maybe you are.