They gave up their authority to regulate trade when the WTO was created through GATT. The US never had a trade minister negotiating trade deals until the WTO was formed through GATT, before that it was entirely the purview of Congress to regulate trade. They also gave up the rest of their authority when they granted the president fast track authority on trade. By doing this they have set up a system where congress is completely bypassed in most trade related issues, and the trade minister and the President have an unconstitutional concentration of power in the area of trade. See Carry_Okie's post earlier on how trade agreements are being used to amend the Constitution in a very stealthy and corrupt way.
Some would equate their acquiesence to treason. Let's hope it's ignorance. The solution it seems is the ballot box..If not now when ?