I am at a $50 Party NL table

I've been at the table for a 5 hands and I've raised 3 of them. I think I may have a maniac image, but I've been dealt cards. I have $51 and the player has me covered.

I raise to $4 w/ . I am re-raised to $9 by the player after me. I call.

The flop is

Do you lead out here? Or do you check raise?

With your table image your opponant expects you to bet the pot, so I thats exactly what I do.
I would say that you have the best hand 3/4 of the time here. Often times this one unit raise is AA but in this case I think it is more likely that he is just trying to isolate you.