What makes you think that Americans want economists to run their country? Because that is what you are proposing. Econoomists nowadays seem unaware of the function of the nation-state, and that people are governed by laws, not economic theory pushed by transnational corporations whose loyalities do not reside with the American people. Yet the freetards among us think you can supplant a self governing nation with theoretical economics which eliminate citizenship of nations and replace it with consumers of regional residency.
You're confusing the freedom to buy and sell goods with the destruction of borders. Hayek, for instance, warned that if the United States encouraged immigration without limits and taught multiculturalism to its citizens, it would fade away into what he called the road to serfdom and eventutally perhaps cease to be a nation at all.
Hayek was of course as determined an opponent of transnational progressivism as he was a proponent of free trade. http://www.unc.edu/depts/diplomat/archives_roll/2002_04-06/fonte_ideological/fonte_ideological.html
They play off of each other rather well. In fact the battle is really between those two ideological entities over the carcass of the once great Republic. Neither is particularly concerned with the people. The people are little more than cordwood fuel for either system.