Peter Beinart makes the case for why conservatives should be satisfied with Romney:
It’s true that Romney could, if he really cared, derail this process, and choose someone with a passion for say, mine safety. But if he did, the decision would produce ripples of discontent: An angry phone call from a Republican member of Congress or large campaign donor. Negative chatter on the conservative blogs. And who would rise in Romney’s defense as he alienated the conservatives who run today’s GOP? The moderate Republican caucus in Congress? Washington’s influential moderate Republican think tanks? The moderate Republican talking heads you keep seeing on Fox? If anyone rose to his defense, it would be the Sierra Club or the New York Times editorial page, which in conservative eyes would compound the offense. A few high-profile decisions like that and the Wall Street Journal would start muttering about the ghost of George H.W. Bush, who lost reelection after a conservative challenged him in the Republican primary.
Assuming Romney can win the general election, this underestimates the incentives Romney will have to ignore conservative discontent once he is in office, and it overestimates conservative willingness to oppose a Republican President. George W. Bush was probably the least conservative President in the substance of his policies since Nixon, but a combination of partisan tribal loyalty, post-9/11 solidarity, and traditional deference to presidential leadership kept most conservatives’ complaints to a minimum or prevented them from being voiced at all. Bush drove through significant expansion of the federal role in education, he pushed through the largest expansion of the welfare state since the 1960s, and he actively defied the party base on immigration during both terms. There were some criticisms and objections to this, but apart from some honorable exceptions there was remarkably little resistance and even less alienation prior to the 2006 midterms. After 2006, conservatives began abandoning the sinking ship, but the immigration debate in 2007 was the only time that Bush faced a large-scale revolt.
Bush assumed that he could take conservatives for granted, and he could, which is what he proceeded to do. Bush presented himself as a conservative while arguably governing farther to the left than anyone, including his father, in the previous thirty years. Most conservatives accepted the act, and largely ignored the substance. If there’s one thing we know about Romney, it is that he is quite capable of pretending to be conservative without being one. He may govern that way for as long as he believes it is advantageous, but there is nothing to stop him from keeping up the pretense of conservatism while enacting policies that are nothing of the kind.