As shown in the picture below, I received 3 badges (so far) for visiting the Stack Overflow election page.
This should be corrected now. The crux of the issue was a race condition that allowed one user to get qualifying user history entries for the badge twice: this then caused the badge awarding logic to try to give them two badges, which violated a constraint and stopped the entire badge award process... After the achievement notification had already been created.
And this kept happening, every time the badge award script ran: identify everyone with qualifying history entries, send 'em achievement notifications, try to award badges & fail... Rinse, repeat.
Nick cleaned up the duplicate UserHistory entries, the erroneous badge achievement notifications, and re-ran the badge awards - successfully. In the near future, we'll try & clean up this logic a bit to prevent future errors.