I've been hearing about the impending "conservative crackup" for nearly 25 years. The term was coined by R. Emmett Tyrrell Jr., the founder of the American Spectator. He meant that conservatism had lost its philosophical coherence. But the phrase almost instantly became a catchall for any prediction of the right's imminent demise or dissolution. These dire prophesies always reminded me of those "Free Beer Tomorrow" signs. As Annie sings, tomorrow is "always a day away." Well, thanks to Donald Trump, tomorrow may be here. There's a fierce internecine battle over whether to oppose Trump's run, passively accept his popularity, or...