Any way you slice it, such an exodus is never the sign of a well-managed country.
The single biggest problem would be rebuilding the US manufacturing base. Once that happens, the US would be fine. America's probably capable of autarky: it's got the natural resources, population size, and technology.
The US didn't impose the condition of being a resource-poor island on Cuba, nor did it impose the condition of economic mismanagement on it (apparently so bad even the Soviets complained about it). The US imposed the condition of a trade embargo, and that's it.