A 50% tariff on foreign workers means you're forcing companies to pay employees in other countries much more than in the US. They obviously aren't just going to shut down their international presence, so that's just transferring money from the US to these other countries. Since the companies would just raise prices in the markets that can most afford it (ie the US), and use those to offset the increased costs elsewhere.
If they're referring to hiring immigrants in the US, it's still kind of the same thing. A 50% tariff on immigrant employees means it's cheaper to just outsource, so now all that money is just going outside. On the other hand, the money the immigrant employee makes is mostly being spent within the US.
If you wanted to limit the ability of companies to pay immigrant workers less, you'd be better off making the initial immigration process harder, but the immigration to permanent residency process faster, that way fewer skilled immigrants get in, but once in they're not exploitable for very long. Since they can't easily import more workers, they're forced to deal with everyone at an equal level.
If you want to limit outsourcing, you'd have to start with onshoring the supply chain and either encourage automation or provide an incentive strong enough to keep those companies globally competitive.
If they're referring to hiring immigrants in the US, it's still kind of the same thing. A 50% tariff on immigrant employees means it's cheaper to just outsource, so now all that money is just going outside. On the other hand, the money the immigrant employee makes is mostly being spent within the US.
If you wanted to limit the ability of companies to pay immigrant workers less, you'd be better off making the initial immigration process harder, but the immigration to permanent residency process faster, that way fewer skilled immigrants get in, but once in they're not exploitable for very long. Since they can't easily import more workers, they're forced to deal with everyone at an equal level.
If you want to limit outsourcing, you'd have to start with onshoring the supply chain and either encourage automation or provide an incentive strong enough to keep those companies globally competitive.