Congress did not write the agreement, nor, under the rules of "free trade" are they allowed to modify the CAFTA.
If you are the only institution that is authorized by Congress to regulate trade, and you don't write the trade agreements and you can only vote yes or no, not ammend or change the agreement, that sounds pretty unconsitutional to me. Or should we call it anti-Consitutional?
Again, they have the power to delegate that authority, which they did...and final passage of the bill was utterly in their hands and no other arm of government...