You may slash corporate taxes to zero if you want and the corporations themselves will thank you for it but it will do nothing to encourage them to keep manufacturing in the U.S. So long as manufacturing offshore costs them less than manufacturing here then they always be tempted to move their business offshore. The only thing that will discourage them is the stick, selectively applied, either by shaming the company or taxing the goods they bring back in some way or some other method. Trump is well aware of that.
Corporations don’t pay taxes, consumers do. A tariff is a tax on the American consumer, plain and simple. No ifs, ands or buts about it. That is the undeniable, indisputable fact. Liberals and RINOs love tariffs and taxes. True conservatives oppose them.