Why does America not tariff outsourced foreign labor?

If America is so concerned about bringing business and manufacturing back to the States, why do we allow corporations to replace American workers with offshore outsourced labor?

Edit: for clarification, I'm referring to white collar/knowledge workers. I think IT, help desks, call centers, digital, etc.

Edit 2: for additional clarification, the solution I'm proposing is that the gov't would create a tax that leveled the playing field between foreign and domestic workers. Thus, disincentivizing any sort of economic benefit to offshore resources and reducing 'brain drain'

*Please, this is not meant to be a political discussion about red versus blue but, a reasonable and logical discourse...as hard as that is for Reddit sometimes. Ha!