"All laws enacted by the Congress of the United States and signed by the President, and all administrative rulings and court decisions made pursuant to those laws, and the consitution of the United States must apply equally to private citizens and to people employed by the U.S. government."
I'm not sure the language is quite right, and it might make sense to add: "unless two thirds of both houses of the legislature specifically exempt a particular group from the law, and state clearly their reasons for doing so." There may sometimes be a good reason to carve out exemptions, so that reservation might be wise.
Update: Here's a list of rules that don't apply to Congress.