The do business in the US and they pay taxes on the business they do in the US. The US tax laws are absurd on this issue.
> there's nothing stopping Congress from enacting laws to tax stockpiled funds.
I am sure that would be help up in the courts for so long it would never see the light of day.
They setup a subsidiary in a offshore tax heaven, transfer their patents and intellectual property to offshore tax heaven, and then route the profits from US company to their offshore subsidiary with transfer pricing tricks.
Some of these companies claim that their headquarters are in Switzerland, Ireland or Cayman Islands. But in reality they are nothing more than a PO box and bank account.
And I agree with you that we're unlikely to see meaningful forced taxation anytime soon based on the current political climate, but that doesn't mean we shouldn't try.