This unique characteristic prevents our negotiators from making a solid deal in a negotiating session. No foreign government will make a deal with us in a negotiation because they know from experience that Congress will ultimately re-write the agreement. No other country negotiates like the United States because they have Parliamentary governments which do not amend agreements. Their Parliaments only accept or reject, so they require us to do the same before they will sit down to serious negotiations with us. If the United States is going to have the opportunity to develop trade policy for the rest of this century and beyond, Congress must provide broad unrestricted trade negotiating authority or else we will be in the position of reacting to the trade policies developed by the rest of the world.
History is full of failed attempts.
My years of experience tell me that the Congress wastes too much time just getting ready to start the negotiations. Congress tries to predict with excessive detail and precision what and how to negotiate. The process takes years, conditions change, what seems important now may be nothing by the time Congress finally must act and vice versa. So let's get started. If the negotiations are agreeable to Congress then it can be converted into the law of the land.