Now that was a debate. Back in 2012 it was the live audience that got rowdy at the presidential primary debates. This time it was the folks onstage, candidates and moderators alike. And somehow it all stemmed from the presence of Donald Trump, the spiritual epicenter of this event, whose outsize persona dominated the proceedings from beginning to end. Things got off to a rollicking start with Trump's show-of-hands refusal to rule out a third-party run and Rand Paul's aggressive reaction. This riveting kickoff set a pugilistic tone for the debate that never subsided.