If you haven’t heard about or seen the clip of Chris Matthews dressing down one of his guests, a conservative talk show host, you might wan to take a look. Aside from the sheer entertainment value of the thing, it might, maybe, be a turning point for the fall election.

Matthews was in his regular Hardball segment where they have a conservative and a liberal radio talk show host to spin the issue of the day. They were discussing the Foreign Policy back and forth between Bush and Obama. The conservative guest launched into Obama as soon as Matthews started the segment, talking about how Obama would be horrible for the country because he was an “appeaser.” Annoyed, Matthews asked him if he knew what appeasement meant—in particular, what did Chamberlain do that was so wrong in 1938? The guy finally had to admit he didn’t know, and Matthews schooled him on some pre-WWII history. I don’t think the liberal guest got to say any more than when you’re in a hole, stop digging. It is high political theater, or, cable news at its worst.

At the core of the discussion was the deployment of “Appeasement” to delegitimate the foreign policy of an opponent. In this case, the accusation was that Obama’s position to talk to foreign leaders with who the US has policy differences would appease them, weakening the US and emboldening America’s enemies. Appeasement, as the Lesson of Munich, has a long been one of the most important analogies used in defining, evaluating, and legitimizing foreign policy choices. Rodger’s post has an excellent discussion of the use and mis-use of the concept, and I recommend you check it out.

What Matthews did was to call the conservative on his mis-use of the term. Rather than simply allow his deployment of the appeasement trope remain unchallenged, Matthews asked: what was it that Chamberlain did that was so objectionable? Its comical to watch the guest stammer and stall, like a student who hasn’t done the readings for class, before Matthews finally gives the class the answer: Appeasement came not from talking to Hitler, but from giving him half of Czechoslovakia. Talking to the enemy is not appeasement. Giving the enemy what he or she wants with no significant concession in hope that the enemy is thus satisfied, that is appeasement.

The Matthews moment means that it may be, might be harder in the future to use such analogies so far out of context. He created an opening to challenge the deployment of such broad analogies and labels, and has forced those who want to use labels such as appeasement to augment their statements by adding the offending act. Now, this could all be for naught, if everyone lets it drop, but it could also be a subtle but important shift in the way this powerful label is used. To pass the Matthews test, anyone on his show now needs to show the dangerous concession. Matthews had defined a rhetorical space in which simply talking to another actor cannot constitute appeasement, and anyone who tries to suggest as much will look like a fool.

Now, this is by no means guaranteed. Matthews could let it drop (but I doubt it, given his tenacity on issues such as this). Moreover, MSNBC has become a much more important player in election coverage (really, its gotten quite good. Olberman is in rare form, Matthews is always fun, and its impossible to top Rachel Maddow). So, if Obama’s opponents want to deploy the appeasement label for him, they are going to have to figure out how to go on Hardball and make it stick. Otherwise, the attack loses some of its steam.

Yet another reason that MSNBC has become must-see TV.