An emailer reminded me of Jonathan Rauch’s rule that successful presidential candidates get to the presidency or vice presidency within 14 years of winning their first major political office. If that principle holds true, John McCain can’t be president; Rudy Giuliani just barely misses the cut; Mitt Romney, Fred Thompson, Barack Obama, and John Edwards could all win; and Hillary Clinton’s chances are a wild card (depending on how First Ladyship counts under the rule).