I think you've got a good point here. There are a number of defenses he could make. The most convincing one would be, "I was looking for a little action, but didn't plan to do it in public." Fine, nothing illegal about that.

But the problem is, he's a senator, and a Republican, and a family-values-conservative. So he couldn't say that. To say those things would be to admit that he's into dudes. That, actually, is probably the reason why he was allegedly soliciting anonymous sex in the first place instead of raising a family with his husband.