Do you think that is, in any way, in keeping without our form of government?
Our Founders warned of foreign entanglements.
I'd say TPA certainly makes passage of trade agreements easier. I'd go further and say it makes trade agreements possible.
The reason we have these congressional-executive agreements in the first place is the nearly universal acknowledgment that you won't get an agreement without them.
If you want to be isolationist and think it's best for us not to have any regulation of international trade, fine, but in the real world trade happens and it's best for us to have some role in setting the rules.
Yeah, amending the Constitution is too difficult as well. Let's just write a work-around so we can pass laws that are blatantly unconstitutional.
Oh, we've done that with the commerce clause already.