The problem Republican "leaders" have is that they don't believe they can win an election if they are "way right" on any issue. And they are probably right, hence the inertia toward the middle. This is the exact same problem the Democrats face, so their "leaders" also move toward the center, at least in their rhetoric. We can't blame Romney for being dull because even if he had far-right convictions, he does not believe voicing them will win him any elections, so he stifles them.
We get the politicians we deserve. Nothing else.