Two responses: If there was a flat tax of some sort, you might be able to say "pay their legally required tax bill" in this conversation, but considering that

Two responses: If there was a flat tax of some sort, you might be able to say "pay their legally required tax bill" in this conversation, but considering that tax dues are the result of a formula derived from a set of laws that span multiple volumes, what is actually due is almost always subject to debate. It's not like paying $3.48 for a gallon of milk. Second, there are always loopholes. Unless you have a vastly simplified system the way you operate your companies' financials will always have a system where there are advantageous ways to structure finances where taxes are concerned. Moving money offshore is always a possibility. You can't force money to stay in the U.S. You can create an environment such that it's the most desirable place to keep it.