Why are pols forcing a theory on us? Free Trade is a theory that has proven to be a disaster.
Follow the money.
I've asked myself that same question, and believe some pols and others who support so-called FT are just pushing a theory they had crammed into their head in college, or that they picked up from some think tank position paper. They think they possess some profound wisdom that trumps all other considerations, so they push it no matter the results for this nation when their theories are partially implemented.
And, then, some pols really are bought and paid for and await their next instructions from major donors.
And I think the transnational corporations just look at the international business situation and try to fashion the trading arrangement that benefits them the most, whether or not it really is free trade. They'd close the US market to all competition if they could get away with it.
And I think most presidents and all the "Masters of the Universe" who are constantly trying to arrange the world to fit their favored theories use trade to influence and win over other nations. I think that's why we end up with many bad deals, and our government tolerates so much cheating by our trading 'partners'. Fair trading arrangements are often not the top government priority. For many of them trade is a major foreign policy strategy and, for the great humanitarians, a way to fight poverty in poor nations. GWB was super-proud of his policies that had helped India so much and created jobs and raise living standards. (Probably mostly outsourcing) - I have heard the occasional pol or think tanker brag how trade has alleviated poverty in poor nations.
I've read how we purposely opened the US markets to Japan in the '50s and '60s to help rebuild them after the war into a strong Cold War ally. Up until the mid-'60s, most all electronics sold in the US were produced in the US, and within about fifteen years, all were coming from Japan.
But I do think many are just theory bound to something they picked up in college, or in the think tank/DC alternate universe. And they are so convinced not much will dissuade them. Their egos need to push their profound wisdom more than they need to assess the actual results.