Without any constitutional amendment----indeed, without even a law enacted by Congress---the Treasury Department has issued regulations barring attorneys from representing specially designated terrorists without first securing a license from the Treasury Department. If an attorney represents such a terrorist without the special license, they'll criminally prosecute him---and possibly even deny him the assistance of counsel.
"Why do the feds hate criminal defense attorneys?" Hornberger wonders. Why, because they're obstacles to illegitimate conduct on the part of prosecutors and law enforcement. "They ensure that the government is not only following the law but also that it's not using perjured or manufactured evidence to convict people who the feds are convinced are guilty."
But in the War on Terror, trivial things as "natural rights" seem to be just obstacles, standing in the way.