> Corporations aren't repatriating the money they hold offshore.

Indirectly, they are: "Nearly Half of So-Called “Offshore” Funds Already in the United States"

Earlier this year, a survey was sent to 27 U.S. multinational corporations and found they held more than half a trillion dollars in tax-deferred foreign earnings at the end of FY2010. The survey also found that 46% of those foreign earnings – almost $250 billion – was maintained in U.S. bank accounts or invested in U.S. assets such as U.S. Treasuries, U.S. stocks other than their own, U.S. bonds, or U.S. mutual funds.

https://www.hsgac.senate.gov/subcommittees/investigations/me...

Yes, an important but never-mentioned distinction is that "offshore" is basically an accounting designation, and that money is not somehow prevented from being put to work in the US.