Buchanan and the inevitability doctrine

This blog carried a post on how Buchanan's reputation reaps little gain from the Centennial doctrine that the war was inevitable. Mitch Hagmaier writes

I had a kid submit an inevitability & Buchanan paper for this year's History Day state semi-finals. He did, in fact, argue that Buchanan was blameless due to the whole Centennial "irrepressible conflict" line of argument, and generally blaming every negative event of Buchanan's term on somebody other than Buchanan. Shame he was more interested in the Sumner-Brooks beating & taking his analysis from contemporary political cartoons than in discussing decisions which Buchanan had actually made, but at least he took a slightly different tack than the usual line.

He's picking something up from pop political culture, I think: any accusation made against your guy can now be refuted by means of rationalization (or charge of hypocrisy). Could be the wave of the future in history...