the button has lots of chip and is in late position.. A-8 suited, 98 suited 66 and any other pair that would make a set are all possiblities. Most likely he reraised you with top pair and a good drawing hand or 66 or a set. With 66 hes drawing enough outs to get ABOUT two to one odds and obviously he feels that even if he was behind he'd still be getting correct odds if you called. I'd call.. big risk = big reward
over pairs don't seem to be a problem at this point.