Today, a blog posting by University of Minnesota political scientist Eric Ostermeier -- noting that National League wins in All-Star games (like the one last night) have historically predicted big GOP House and Senate gains -- is receiving a lot of attention this morning.
Here's Politico: "[A] National League victory in the Mid-Season Classic has preceded every election with double-digit GOP House gains since 1950. The pattern is similar in the Senate. Since 1948, every time the Republicans have gained at least five Senate seats the National League has won. The flipside, however, is also true in the upper chamber: American League victories have preceded Democratic gains of five or more Senate seats since 1948."
But it's important to point out that a National League All-Star win hasn't always GUARANTEED big GOP gains. Example: In 1996, the last time the National League won the game, Republicans picked up two Senate seats while Dems picked up three House seats (and Bill Clinton won re-election).
Indeed, Ostermeier makes this point:
A National League victory does not guarantee major GOP gains in the House - it has been a necessary but not sufficient condition for Republican success in modern political history. (National League victories have also occasionally preceded big gains by House Democrats: in 1964, 1970, 1974, and 1982).
However, over the past 60 years one thing is for certain: an American League victory in the summer classic has meant either only modest gains by Republicans in the House (in 1962, 1992, 2004) or, more likely, gains by the Democrats (in 1948, 1954, 1958, 1986, 1988, 1990, 1998, 2000, 2006, 2008).