The Obama administration is currently negotiating with 11 other nations on a Trans-Pacific Partnership, which is intended to remove barriers to trade and investment and establish clear rules of the road. In preparation for submitting the deal, the administration wants "trade promotion authority," a long-used option that says Congress may accept or reject any such accord but may not amend it.
Opponents of trade reject both proposals. They don't want to expand commerce with these countries, which range from Japan to Chile (and don't include China). They know that without trade promotion authority, getting a deal done would become virtually impossible. No country is going to agree to a large package of provisions if Congress can step in and veto any it doesn't like.
But it's hard to frighten voters with tirades about congressional voting procedures. So, as Steve Chapman explains, the critics are falsely depicting the whole process as one of ominous secrecy, whose sinister effects will be known only after it is too late to escape them.