I tend to agree with you. How did Romney ever manage to win more republican votes in the primaries than Santorum and Newt, I can not figure out.
Infighting.
There was a pretty good clue if you lurked around this forum from about mid-January to late March.
The Newt people were constantly sniping at Santorum for being a less than perfect conservative.
Most of us Santorum supporters agreed that he had his imperfections (who doesn't?) but was still far preferable to the post 1996 version of Newt.