Fast Track authority lets the president submit a bill for a mandatory vote by a deadline, with no amendments allowed, Senate rules waived and debate limited in both chambers of Congress. Fast Track expired in 2007, so President Obama must reinstate it to pass the TPP. Look for that to happen this summer.
Margaret Flowers and Kevin Zeese at truthout explain why Fast Track is unconstitutional:
Under Fast Track, the president was allowed to negotiate and sign trade agreements with whatever countries the executive branch selected - all before Congress voted on the agreement. Fast Track meant that the Congressional committee processes were circumvented and the executive branch was empowered to write lengthy implementing legislation for each trade pact without Congress. These executive-only authored bills required US law to conform to the trade agreement...
Indeed, Fast Track turned the US Constitution on its head. Under Article I Section 8, Congress has exclusive authority "to regulate commerce with foreign nations" and to "lay and collect taxes [and] duties." Under the Constitution, the president is empowered to negotiate treaties, but Congress must vote to approve them. Thus, Fast Track took constitutional power from Congress and prevented the checks and balances needed to prevent an imperial presidency.
For most of the history of the United States, treaties and trade agreements went through the normal congressional process described in the Constitution. Fast Track is a relatively new concept that coincides with an era of increasing presidential power... If Congress had reviewed agreements such as the WTO and NAFTA beforehand and civil society had been able to participate in a democratic process, would the United States have made the mistake of passing these laws that have so injured our economy and others?
Fast Track is very unpopular, so now President Obama and others who advocate for it do not use the term. Instead they call it by the euphemism "Trade Promotion Authority." But changing the name does not change what it is - a method of ceding the constitutional power of Congress and undermining the checks and balances built into the constitutional framework.
Congress needs to consider what agreements such as the TPP will do to jobs, trade balances and the environment. Since Nixon, Fast Track has been used by presidents to go way beyond trade and tariffs. These agreements have been used to change US law by establishing "rules related to domestic environmental, health, safety and essential-service regulations, including deregulation of financial services; establishment of immigration policies; creation of limits on local development and land-use policy; extension of domestic patent terms; establishment of new rights and greater protections for foreign investors operating within the United States that extend beyond US law; and even limitation of how domestic procurement dollars may be spent."
Thus, not only has the constitutional power of Congress to regulate commerce with foreign nations been undermined, but a whole host of domestic laws have been rewritten to satisfy international trade.