Are you going to take the word of “economics” or are you going to listen to the likes of I Am Sam and the first guy to get killed by the Predator?
To a very limited degree I agree with some subsidies. You have to have farmers in America. You can’t have all your food imported, though it may be more economical to do so. Why? Because then America risks having it’s food supply cut off at any time.
Same with anything, coal or steel or anything. You can’t risk having valuable resource under the control of another nation.
With that said, you have to strike a balance. You need to subsidize only so much so that if there is a cutoff we can use this limited amount till America is able to produce it’s own supplies again. We need a continung supply of people with knowledge to grow food or make steel or whatever, in case of an emergency type of deal
The key is balance. That doesn’t work out in real life.
Another factor is that the Senate is an unequal body. Wyoming with half a million people has as many senators as California with 37 million. This accounts for a lot of the influence of agriculture and mining in congress.