passed for the purpose of excluding the pe litioiiemnd all others similarly situated—to pnnishbv excluding them from the United States courts. It was not for conduct subse quent, but antecedent to the passage of the. statute. This act comes within the clear meaning of the clause in the Constitution that Congress shall pass no erpitst facto law or bill of attainder. No rights can be taken • away by law uuless the accused shall be first