Look at it this way, the Delaware State Fair grounds is a"no carry zone" by their own policy. Just because there is no written state law making it unlawful, does not mean it's smart to carry there. If you are caught carrying, more than likely the patrolling State Police will be called into the situation. You maybe unlucky enough to get a officer that is anti-gun, and while the lawa is, what the law is. this can end up very bad for you. Is it worth the risk to be on the short end of the deal. Get kicked out, and have to take your family home because you couldn't follow policy. I suggest if you won't leave your gun in the car/truck, or at home, best thing is to not go at all. Call it a protest, or what ever makes you feel right.
Good luck trying to convince your kids that you had to take them home from the "Fair" because you couldn't follow the rules. Remember kids watch and understand what you do, and mimic your ways. Is this sending them the right lesson, just so you can "feel right". I think not. The correct message to send them is that sometimes you have to do things in life, wether you agree with it or not.