bq. A party holding the governorship is an advantage in a presidential contest, though it doesn’t guarantee a victory. The correlation between a governor’s mansion and winning elections is much stronger when it comes to Senate contests. Since 1995, almost three quarters of the Senate seats Republicans have picked up have come in states that either had a Republican governor serving at the time or had a Republican gubernatorial candidate win the same day.
The first statement, regarding presidential elections, is wrong — if we interpret “advantage” to mean “presidential candidates get a statistically significant boost in states where their party controls the governor’s mansion.” See this earlier post.
The assertions regarding Senate elections present interesting correlations, but these could be due to many factors other than the power of a governor. Wilson’s calculations suggest that Republican candidates have picked up Senate seats in states with (1) a Republican governor or (2) a winning Republican candidate. Correlation #1 could simply arise because the demographic or partisan composition of a state is conducive to electing Republicans to both offices — arguably because the state tilts toward the GOP overall or is evenly divided enough between the two parties that either one could easily win a seat. Correlation #2 could arise for this same reason and also because national conditions in a particular election year are conducive to Republicans winning generally.
Reid wants to suggest that governors help presidential and Senate candidates because they control “the best existing machines in their states.” But his evidence is consistent with many other stories that have nothing do to with a governor’s personal political organization.