Few Americans remember Quemoy and Matsu, but they were a key issue in the 1960 debates between Kennedy and Nixon.  These Taiwanese-governed islands lie just off the coast of mainland China.  A couple of times during the 1950s, the communists had shelled these islands, only to stop when Eisenhower rattled American sabers.  During the second, third, and fourth debates, Nixon insisted that we should defend the islands while Kennedy said that they were strategically indefensible. 
Last night’s debate related to the Quemoy-Matsu exchange in a couple of ways.

Nixon did well on the issue, performing much better in the later debates than in the first.  But to the extent that the debates moved opinion, it was the first one that counted most.  Last night, McCain gave his best performance of the three debates, but will it make any difference on Election Day?  Probably not.

Quemoy and Matsu soon faded in the public mind.  Similarly, Joe the Plumber should enjoy his moment of fame, because he will disappear from the news very soon.  The difference is that defense of the islands was a genuine issue.  The mention of Joe the Plumber was a gimmick.  The focus on Joe is more evidence that the debates of recent elections were far less substantive than those of 1960.