Once corporations have exhausted their large hoard of overseas cash, the amount they repatriate will go down significantly. So isn't this really just a short-term boost?
I'm not saying this is definitely the case, and I would love to be proven wrong. I just don't see how a tax cut would have corporations scrambling to return jobs to the U.S., instead of having both a tax cut AND cheap foreign labor.
Ideally the US begins stealing corporations and manufacturing from the rest of the world, whereas previously the flow had been going the other direction, with dozens of large companies abandoning the US for lower tax locations.
For example, the lower corporate tax rate, combined with very inexpensive US energy (cheap natural gas), makes manufacturing in the US even more appealing.
You don't have to beat all the other tax havens, you just have to get low enough to be competitive on the overall value proposition. The UK is at or going down to 17.5%, that 3.5% variance with the new US rate becomes mostly meaningless as an issue (17.5% vs 35% however is a drastic gap).