Boy, I hadn’t read this about McCain before now. I really feel for his first wife. She went through so much herself.
https://www.forbes.com/sites/robertwood/2017/02/02/another-travel-ban-irs-moves-to-revoke-passports-for-unpaid-taxes/#3872c5b140fb
Another Travel Ban: IRS Moves To Revoke Passports For Unpaid Taxes