The CNN South Carolina debate was, hands down, the most entertaining debate to date. I hardly missed Herman Cain at all.

I don’t know if it was that the field is narrowed to four, and all of them professional politicians at that, or if it was how late we are in the process, or perhaps it was just changing incentives as the strategic positions of the candidates change…but, finally, at long last, after what feels like hundreds of debates, the not-Romneys tonight opened up their opposition research files on the prohibitive favorite for the nomination. And, yes, they left plenty of marks — although whether it will make much difference is another question altogether. That, and one of the more shockingly personal attacks ever, by Rick Santorum against Newt Gingrich.

But first: All of that was perhaps overshadowed by the first five minutes of the debate. CNN’s John King opened things off with an absolutely awful question, asking Newt Gingrich about his (second) ex-wife’s newish allegations that Newt had asked her for an open marriage. He responded with an angry, vicious, nasty, and — in a GOP primary context — enormously effective attack on the press. Never mind, of course, that this was the same Newt Gingrich who spent the first half of 1998 vowing to never give a speech without mentioning Monica Lewinsky (although it’s also the same Newt Gingrich who spent October of 1998 attacking the press for daring to talk about Lewinsky instead of the Serious Issues he had realized might play better for Republicans). Or that it’s the same Newt Gingrich who later, in the context of Romney’s tax returns, argued that the party couldn’t be nominating anyone who would later have things revealed about him that would hurt in the fall campaign. Never mind any of that; King couldn’t have set Newt up any better, and if there’s one thing that Newt Gingrich is never going to fall short on, it’s demagogic attacks that are in tune with his audience. If TV news people use that first five minutes as their sound bite from this debate, it’s certainly going to help Newt in South Carolina and beyond.

If they don’t, however, there sure is plenty of other good stuff to run. Finally, the attacks on Mitt Romney got plenty of time. On (as Tim Pawlenty once put it) Obamneycare — that is, on the similarity of Romney’s health-care plan in Massachusetts to Obama’s Affordable Care Act. On abortion, including abortion coverage in that Massachusetts plan. On Bain, although Newt pulled his punches on that one. On releasing tax returns. All of those got full, sometimes extensive, attack time. Others, including climate, received at least brief mentions. Romney handled most of it fairly well, although he stumbled badly on the relatively easy question about his tax returns, but the truth is that these are all attacks that should play very well with Republican voters. The more time spent on them, the worse it is for the frontrunner. And by that standard, this was a debate that was very bad indeed for Mitt Romney.

And that wasn’t all. Rick Santorum came ready to attack — he took the lead in an issues-based attack on Romney, but also made a sustained, highly personal attack on Newt Gingrich, adding up to a case that conservatives absolutely cannot trust Newt. It was hard for me to judge how all of that, or how Newt’s defense that he was just too “grandiose” for ordinary folks such as Santorum, played. But Mitt Romney’s prepared hit was, I have to believe, devastating; Newt’s been claiming non-stop that he “worked with” Ronald Reagan, but Romney noted that Reagan’s diaries mentioned Newt only once, and not in a flattering way at all.

I should mention Ron Paul. He was there, too! And unlike in the debate earlier this week, his loyal audience was in the debate hall, at one point booing down John King when he didn’t give Paul an opportunity to speak on one question. But he didn’t engage nearly as much with the others as he’s done in the past.

As usual, what matters less is what was said during the nearly two-hour slugfest than what the news media, especially the Republican partisan press, chooses to highlight. Pick the right clips, and Romney actually looks just fine. Pick the right clip, and it was a great night for Newt. Or pick a different set, and watch Romney or Gingrich just get hammered. At least this time there was plenty to work with. If you like presidential debates, you’ll want to go back and watch the rebroadcast of this one; it was a doozy.