With just two major Republican debates remaining before the Iowa presidential caucuses, Donald Trump has been remarkably lucky. The only major candidate who could actually inflict lasting harm on the vulgar poster child for inherited wealth, and the only one who could readily attract and hold some of Trump's blue collar constituency, is the only one banished - by the idiotic, poll-driven debate rules to which the feckless Republican National Committee acquiesced - from sharing a single stage with The Donald. For reasons both stylistic and substantive, Pennsylvania's former U.S. Sen. Rick Santorum could eviscerate Trump in a direct encounter....