I don't think an effective Republican consensus will be built. At nomination time there might even appear to be an enthusiastic endorsement of one candidate, but I think it will collapse by November. Why? First because the divisions within the GOP ranks are too deep. A variety of social and fiscal conservative groups will perhaps give half-hearted support, but not be willing to really work for a Romney, or pull the lever for him. Gingrich was right. Only 25% of Iowans liked Romney. Every other potential candidate has a similar or larger faction opposed to him. Compromising their principles to support their party's choice will in the end seem as unacceptable as an Obama win.
Secondly, the superPACS will deepen divisions and make compromise far more difficult. The Iowa experience is a bit of a political science phenomenon. In just a few days Gingrich was ripped to shreds. You could say he's an easy mark, but it's time we recognize what a large portion of the public are swayed by these powerful messages. Opinions and support will shift at warp speed all year. At election time I think many Republicans will be so disillusioned by their party's 'chosen one', that they will stay home. That will be the deciding factor, especially in the swing states.