You are probably on several mailing lists that Romney bought and consolidated and has resold. I get mountains of email from GOP candidates and causes that I never signed up for - some I never heard of before. They got that email address [which is a throwaway for just this purpose] from a newsletter signup or a candidate donation list which was resold.
Hubby doesn’t sign up for political email nor does he donate to candidates online. He’s very careful with his main email addy. It was one of the reasons this email was so odd.