Check out the star insignia for Rear Admiral, Lower Half. The star is, of course, repeated as insignia for all general and flag officers in all branches of the service.
Take a look at the star in McCain's campaign logo. Or a closer look.
McCain, of course, is not and was never an admiral, topping out with the rank of captain. (Captains get a little eagle.) His campaign website bio neglects to mention his rank at any point.
Is that ridiculously petty of me to point out?