Leave them like they are now, except, for businesses that employ greater than 90% of their workforce (excluding sales staff*) US citizens are completely exempt from corporate income tax. Businesses claiming to fall into this category but actually employing less than 80% their entire non-sales workforce US citizens get penalized in the form of double whatever their corporate taxes are.
On the state level, allow businesses employing more than 90% their non-sales workforce as state residents exempt from any state income taxes.
* Overseas sales staff implies that product and/or services are being exported, thus promoting a positive balance of trade. This plan allows for native foreign sales staff to be freely hired if useful to promote this positive balance of trade.