Correlations

nexstarman mentions that CNN has been harping on how since 1980 the winner of the South Carolina Republican Presidential Primary has always gone on to win his party's nomination.

How impressive is that, really? From 1980 to 2004, there have been seven US presidential elections. Of those, 1984, 1992 and 2004 had an incumbent Republican president running for reelection who was the party's obvious standard-bearer. That leaves four seriously contested nominations.

In 1988, Vice-President George H. W. Bush was the party's heir apparent; he unexpectedly lost Iowa and New Hampshire, but he had vast advantages in money and backing and came back quickly. Similarly, Bush himself had beaten Ronald Reagan in Iowa in 1980, but the primaries consolidated behind Reagan (who had had a significant following in 1976) pretty quickly. Since in both cases South Carolina was an early place where the general trend revealed itself, I suppose you could call it a useful indicator in that sense, but you probably could have called it without looking at South Carolina. (The real lesson here is that the Iowa caucus is weird.)

So... I guess we're basically looking at 1996 and 2000 as races where the nomination was seriously in doubt and South Carolina picked the eventual nominee (I'd guess its reputation is largely the result of its being McCain's Waterloo in 2000). Pretty amazing, eh? I should go into this business. It's kind of like spouting football stats.