The same is not true within the Republican Party. On what basis will the party unite? On fiscal responsibility? Romney and his cohorts have said nothing about serious entitlement reform; the Tea Party, meanwhile, calls for it daily. On taxation? Romney has a 59-point plan that smacks of class warfare; the Tea Party wants broad tax cuts across the board. On health care? Romney and much of the establishment aren't against the individual mandate in principle; the Tea Party despises the individual mandate as a violation of Constitutionally-guaranteed liberties. On foreign policy? Paleoconservatives want a Ron Paul-like isolationism; neoconservatives want a George W. Bush-like interventionism; realists want something in between.
There is the very real potential for the Republican Party to spin apart in the near future. It could easily become a set of regional parties knit together by opposition to extreme liberalism. Chris Christie and his followers don't have all that much in common with Rick Perry and his followers. Never has that chasm been so obvious.
The Republican Party is like a bed of nails. It works so long as the nails are relatively close together -- but as the nails are moved further apart, the chances of winding up spiked from head to toe grow. Right now, the nails are too far apart. The Republican Party is about to be cut to shreds, even as the establishment declares victory over those redneck insurgents from the Tea Party. Romney's victory may very well end up being pyrrhic for the GOP in the end.