I don't recall any dress code in the Capitol when I went as a kid.
I'm sure its like what a lot of bars do. That is, the dress code is determined when you walk up to the door, and they decide if they want you in there or not.
So if there really is a dress code for the Capitol, what is it? And show me a link. Because I'm sure if there is one, it would be made public, so that visitors could be sure to dress properly. I sure as hell can't find one here
http://www.aoc.gov/cc/visit/index.cfm
I think you guys are making this up. There is no dress code, provided you are dressed in a manner which would be legal outside the capitol, of course. You righties always make stuff up when it suits you.