That's what's at issue.
"Us all" - what do you mean by that term?
It is quite unlikely that ALL of "us" would be poorer under a strict protectionist scheme.
OTOH, it is VERY likely that all of "us" will be poorer under a global political scheme.
Unless you want governance to go the way of the economy, you'd better get behind national economics.
By "us all" I mean every last American. We are all consumers. The first thing that would happen under a protectionist scheme would be tarrif (tax) increases. This would mean the cost of everything would go up, foreign and most likely domestic. This alone would make us poorer.
And since nothing occurs in a vacuum other countries would follow suit and hike tarriffs on our exports, which are not insignificant. This means job losses.
OTOH, it is VERY likely that all of "us" will be poorer under a global political scheme.
I think I see the root of the disagreement.
You view world trade as some sort of managed scheme for the beneifit of some shadowy cabal. I see it as the recognition that capital and labor flow to where they are most efficient and trade frees up people to not only enjoy a higher standard of living but also produce the things in which they have a comparative advantage.