Again, pleasure is subjective, of course there is not going to be hard evidence that it gives more pleasure. The same way there is not going to be any hard evidence that getting whipped, having candle wax melting on you or getting **** on, is pleasurable. It is a person by person thing, some people thing having their johnson tossed in a mouse trap is a 10/10 on the pleasure scale, personally i would harm a person for trying it. Some people may want to be circumcised later, some may not, sex is one of the most subjective things out there, to sit there and demand hard proof that it makes sex more pleasurable is simply silly.
It is not an issue of benefit, it is an issue of being able to make the choice yourself, and you saying " i wouldn't care if i was circumcised " makes about as much of a point for it as me saying " I would break someones hand if they tried to circumcise me.".
Once again, if it is "not an issue of benefit," then there is no issue in banning it. If you cannot show me evidence for the following:
1. That circumcised men REALLY do care that much about not having a foreskin.
2. That circumcised men are somehow inferior to men who are not.
3. That it reduces pleasure.
4. That is harms your health.
Otherwise, you have no argument, because
circumcision is a normal part of religious practice for billions and billions of people across the planet, and which also happens to be protected by the first amendment.
Which is to say, none.
I had the choice to get circumcised at any point and i choose not to, you have had that choice removed. Even if i accept your " I can tell if i want it, and i don't." at face value, we have two people , one who says they prefer being circumcised , one who says they prefer being not. obvious proof that attitudes on circumcision vary by person. So to take away this choice, which we have solid proof that people feel differently on from your child, is simply not right. If i ever felt the want to go get circumcised , i could. You on the other hand, if you ever wanted a foreskin are f'ed.

You are assuming that circumcised men care. I have a question for you: Since you yourself are not circumcised, or a part of a major religion, what stake do you have in the argument?
And no, if I REALLY wanted a foreskin, I am not "f'ed" as you say. I can get plastic surgery done to remove skin from my thigh or someplace, and have it sculpted and graphed onto the spot where my foreskin used to be. So the choice is still there.