> And the prosecutor may admit evidence of what the President allegedly demanded, received, accepted, or agreed to receive or accept in return for being influenced in the performance of the act. See 18 U. S. C. §201(b)(2). What the prosecutor may not do, however, is admit testimony or private records of the President or his advisers probing the official act itself.

The argument is not that all recordings are off limits, but if the President asks his lawyer "what is a bribe?" that can't be used as evidence he took a bribe.