If you want to know why the establishment so vociferously supports Romney and so despises Gingrich you need only listen to Newt's CPAC speech for the answer. Speeches from all three major presidential contenders are included at the featured link so I will not repost them here. I listened to all three. Newt wins speech of the day hands down, in my view.
I suggest first posing the question, "What will this candidate do as president?" Then listen to the speeches for the answer. Only one candidate answers that question with specifics. Only one candidate presents himself as a true reformer. Only one candidate makes bold predictions, plans, and promises. That man is Newt Gingrich. It is not a close contest. Gingrich's speech is loaded with specifics. Newt's boldness is exactly why the Republican establishment not only hates him, but fears him. He is a threat to their very existence. If Gingrich only accomplishes half what he promises as president, I will be ecstatic.
By contrast, Romney's is a speech practiced in cliched conservative abstractions. Mitt does promise to defend traditional marriage and promote pro-life policies, but those are rather safe positions in the current climate that fail to distinguish him from the others. Mitt will be no more pro-life or anti-abortion than Santorum or Gingrich and he may well be less. At least he mentions Hayek. Unfortunately, I suspect it's no more than a crowd pleasing name-drop. "We need bold and sweeping reform," Romney says. (Gotta be sure and get that "reform" buzzword in there.) He promises to cut the budget and "get rid of a lot of programs." "I won't just slow the growth rate of government, I will actually cut the spending of government." "I will eliminate ObamaCare." Mitt plans to get rid of a large number federal employees. Romney's is a speech steeped in vagueness. I see your lips moving, but I can't hear what you're saying. It must be the RomneyCare and automatic minimum wage increase background noise.
Santorum's speech can be summed as "I will be principled." If you get more out of it than I did, let me know. Surprisingly, I found Santorum's speech even more vague than Romney's. But I believe every word that Santorum says. I can't say that about Romney.