No, what would happen is not that corporations make less money, but that you see actual offshoring grow again.
I am a former H1-B, now permanent resident, soon citizen. Do you really think I'd just not be as good a programmer here and I am back home? The difference is that here I can get paid like Americans do, and back home, I'd be making between half and a quarter of what I make here, probably for a similar corporation.
I had one of those vaunted H1-B transfers, when my first ever employer decided to move all R&D that was being done in the US to Brazil. Some jobs remained in the US, but none of those that a good programmer might want: They hired the cheapest, least experienced American programmers they could get away with for customizations and customer-specific bug fixes, on top of the now Brazilian codebases, and hired all the senior programmers in Brazil. A Brazilian working from Brazil is far cheaper than if he moves to the US and competes with Americans directly, buys in American shops, and pays American taxes.
So instead of getting foreign programmers to compete with Americans in a way that concentrates the talent here, you'd make programming a big growth industry pretty much everywhere else. It might be helpful for a few years, for the experienced American programmers, but like other forms of protectionism, the trend would be negative for programmers in the US.