To me it's not all bluster. But I agree here in the loopholes are hard to close with entrenchment. The paid for definitely rests on way more sound math than republican 'job growth -> gdp' magic.
There is quite a lot but just a few things I quickly googled:
- calculate 21% tax on country-by-country basis, eliminate tax-free 10% foreign point of return - make it harder to invert by acquiring/merging foreign companies to offshore profit - eliminate tax benefits for “Foreign Derived Intangible Income” (e.g. shift IP abroad i think apple does this?). I think this one also moves those incentives stateside which would be good
https://www.cnbc.com/2021/03/31/biden-infrastructure-plan-to...
https://www.whitehouse.gov/briefing-room/statements-releases...