Is there a correlation between attractiveness of a presidential candidate's spouse and their chance of winning?

This topic appears very misogynistic, but I swear it's for science. 

I've been looking at candidates over the past few decades, and the patterns seems clear: the candidate with the more *physically* attractive spouse has won.

Went back to Nixon/McGovern. Some of the first ladies were well past their prime at the time of the election. But generally speaking, the candidate with the easier-on-the-eyes spouse seems to triumph.

Am I wrong? Are there any exceptions over the past century or so?