Predictive Power of Primaries

I like to tell my students that we are (w. the exception of 2008's Democrats) shrinking the primary season and selecting the nominees earlier and earlier.  Well Nate Silver of 538.com is now doing a three part series looking at the predictive power of presidential primaries.  The first one shows that from 1972-2008, only one Republican was not selected based on the predictive power of the early primaries and that was John McCain.