I think you overstate the negatives. Assuming the $300k/year/displaced worker figure is accurate, I'd guess the other important figures are more like:
* Workers currently paid on average $40k/year will lose their jobs.
* They will get new jobs paying on average $60k/year
* The businesses that pay them will get an extra $200k/year in profit.
I pulled those figures out of thin air, but you can play around with them and see that it's very easy for a trade agreement to be good for everyone while still being disproportionately better for the people who control the business.
What is most objectionable are the 2/3+ of the agreement that is about things like corporations suing states, extensions of excessive copyright and patent laws, etc.
The other problem is that the American worker took it in the shorts after NAFTA. A bunch of jobs suddenly moved to Mexico, and then to Asia.
The United States would have benefited more from automating those jobs rather than just having them leave. Had NAFTA not gone into effect, companies would have had to do more automation.
While people can be in general better off, I still think the situation is unfair and it's reasonable to oppose the treaty just on the question of fairness, but that's a much more complicated conversation.
* Workers currently paid on average $40k/year will lose their jobs. * They will get new jobs paying on average $60k/year * The businesses that pay them will get an extra $200k/year in profit.
I pulled those figures out of thin air, but you can play around with them and see that it's very easy for a trade agreement to be good for everyone while still being disproportionately better for the people who control the business.