Of course the counter argument is that we should trust Congress and POTUS to do the right thing. Which side of that argument are you on?
It isn't a matter of trusting them to do the right thing - just being realistic. Every modern trade deal has been implemented as an executive-congressional agreement, as proposed for TPP. There are very practical reasons for this.
If you're against trade agreements so be it, and TPP may well be a bad deal for us, but I think this whole secrecy thing is a red herring.
Good. The more leftists they run the faster they vanish.