In his column in today's New York Times (here), David Brooks says we do because the current crop of anti-government Republicans will never garner a national majority and are incapable of changing the way they think.
I found this column a real head-scratcher. First, how would such a "moderate" wing emerge in a party that has gerrymandered congressional districts to the point where only extremists need apply? Anyone who runs as a traditional conservative, let alone a moderate, is bound to face a primary challenge from the right. And that's true even for Republican politicians running at the state level - witness Richard Lugar's primary loss to Richard Mourdock.
Second, why would Republicans want their party split into more parts, even if that could be achieved? The Republicans already are (at least) two parties: the neo-conservatives and the paleo-conservatives (including most Tea Partiers). Indeed, one might argue that a group of anarcho-libertarians, represented by the Paul family, for example, constitutes a third wing of the party. I would love to think there is room for a new group of moderate Republicans (does anyone remember George H.W. Bush circa 1970?), but outside of a few states in the extreme Northeast of the country, that is an extinct species of Republican. And, even if they could be cloned back into existence, could they compete against Clinton-style "New Democrats"?
Ordinarily, I consider David Brooks as more or less a realist. But today's column falls under the heading of "wishful thinking." And I'm not even sure it makes sense for him, as a Republican, to wish for what he's thinking.