I agree with vtzl that this was the wrong hand to defend with, not only because of the bad math of the hand, but it also really messed with your table image with this guy if you had to show this hand down. Once this kind of player sees you show down a hand like that he is coming for you. He will be at your blind and he is upping his aggression every time you limp in a pot.
I am wondering why this guy is playing almost every hand for a raise. Is he a guy on a rush? Is he a guy on a kamikaze mission or is he guy playing a loose fast strategy against a table full of tight players?
If the player is a rush player or kamikaze player they will not tend to fold. The kamikaze don't care what he needs to invest to make a hand and the rush player thinks any hand he plays is going to turn into gold.You got an excellent flop for that particular hand. If this guy is playing a rush or kamikaze, there is really not much to do except figure your outs to draw and draw if he gives you the price as vlzvl suggested.
But if the player is playing a strategy to pick up a lot of small pots with an aggressive raise and follow up bet. Take the lead from him. If you have a drawing hand that would justify calling a pot size bet, make the bet into him instead of calling his bet. Make that ace on the flop look like yours instead of letting him make it look like his.
A player that is just raising and doing a follow up bet to pick up the small pots: unless he has hit something fairly big he is going to back off and let the hand go with a lot more frequency then the other two types. If he is making this play almost every hand, he is pretty much playing random hands and his pre-flop raise is no good indication of the range of cards he might hold. Semi-bluffs into this guy should have better results then check calling him.
This guy is playing loose aggressive against the table, and what needs to be done with him is to play tight and more aggressive. Don't let this player keep the lead pre-flop when you have a strong hand, take the lead from him and let him call bad or leave dead money in the pot. You can't do that playing 9-5 suited, he has an advantage over you if he is playing blind and out of position.