Congress is in an uproar over a situation caused by the low quality of their own work. Apple established a subsidiary incorporated in Ireland with operating HQ in Cupertino.
Well under US law a company location is deemed to be where it is incorporated. EVERY OTHER country holds it to be where the headquarters is. So this operation as far as Ireland is concerned is a US company, and as far as the US is concerned is a Irish company.
This means it doesn't have to file taxes ANYWHERE.
All it would take is some reasonable tax codes to prevent these shenanigans. But NoooOOooo.
So now we get the Congress holding a circus to excoriate Apple. But really the fault is their own.