It’s been fashionable to call Joe Biden a "gaffe machine," especially in the run-up to last night’s debate, which featured endless suggestions that the Delaware senator would be incapable of restraining himself. But those critics had either ignored Biden’s debating history or were oblivious to it, because he has actually been one of the instinctively strongest, most versatile and – yes – self-controlled debaters in politics.

As I wrote a few weeks ago, one parallel between an earlier Biden debate and the challenge he faced against Sarah Palin stood out.  The year was 1972, and Biden was a 29-year-old first-time candidate for the U.S. Senate, challenging 63-year-old Cale Boggs, an institution in Delaware politics. When they debated, Boggs was asked a question about an obscure international treaty. As he fumbled and stammered to produce a coherent response, it became obvious he’d never heard of it. Biden, though, did know about the treaty, and could have jumped in to show it. But he also knew how that would look – the know-it-all-up-start rubbing it in the old man’s face. So when it was his turn to speak, all he said was, "Aw, I don’t know that one either."

Most politicians wouldn’t have been able to resist that – but Biden did. And then there was last night, when Palin challenged Biden’s assertions about recent statements from the U.S. commander in Afghanistan by talking about what General "McClellan" actually said. She seemed oblivious to the general’s real name: David McKiernan. (She made two separate references to "McClellan.") The caricature of Biden that the media favors would have jumped right in, condescendingly pointed this out, and come across as a boor. Instead, he said nothing, treated her respectfully all night, and won high praise afterwards for his strong, knowledgeable and surprisingly gaffe-free performance.

But it was no surprise to longtime Biden watchers. As the candidate himself said last night: Past is prologue.

Follow Steve Kornacki via RSS.