With the Iowa caucuses just days away, the Republican crack-up threatens the future of the Grand Old Party more profoundly than at any time since the GOP's eclipse in 1932. That's bad for America. The crack-up isn't just Romney-the-smooth versus Gingrich-the-bomb-thrower. Not just House Speaker John Boehner, who keeps making agreements he can't keep, versus House Majority Leader Eric Cantor, who keeps making trouble he can't control. And not just the GOP establishment versus the Tea Partiers.The underlying conflict lies deep in the nature and structure of the Republican Party. And its roots are very old. As political analyst Michael...