One side likes high skill immigrants but does not like low skilled immigrants. The other side likes low skilled immigrants and thinks high skilled immigrants are a-ok too. To try to get their way, the low-skilled side says we won't pass your high skilled stuff unless you pass our low-skilled stuff. The other one refuses and you have legislative deadlock that prevents changing much of anything.

That's what I've heard about the problem currently.

Also I wouldn't base it on federal taxes, because people with state taxes will pay less federal tax since the state tax is a federal tax deduction or similar. I would base it on total USA tax load.