The Center for Tax Justice has an analysis of how these large, US multinational companies (a/k/a “global” companies) use clever accounting to record profits—$16 trillion in total—offshore. This is so, even though the profits may have actually been generated in the United States.
Because these profits are designated as offshore, the corporations get to defer US taxation on them.
In other words, regular American taxpayers pony up the money, year after year, to fill the gap for taxes not paid by these multinationals. They are a tax law unto themselves, courtesy of the tricks their lobbyists got Congress to vote on.