Here is the story. The unions are dead. There is no reason to have unrestricted trade if the reason is to break the unions. Union membership is at 6%. During the 1930's ALL trade was less than 5% of the ENTIRE GDP. So either way smoot-hawley had no impact on the duration or depth of the depression. It is a red herring argument and totally irrelevant. There are 22 right to work states were non union workers can produce product at a profit.
The unions are dead. Unions run the State I live in. The Democrat Farm Labor mafia has a stranglehold on everything that happens here. Do you really think Dayton got elected because he's likable or a good choice? No. Because the DFL Unions went to bat for him.
Same for Detroit. California. Etc...
The reason for free trade is freedom. Period. Anything less is Statist bullsh*t.