Federal Law takes precedence over State Law. So if the Federal Government passes the Civil Union Act stating that Marriage is a Religious device and thus unconstitutional under the U.S. Constitution, and then replaces the office with Civil Unions, the States could complain, but they couldn't do that much. Well, take the law to Federal Court and complain to the Supreme Court maybe, but at that point you have a State out-and-out stating it is being prejudiced because I'm quite sure if would be one of those States that forbid Gay Marriage doing this. ^^;;