Tony MacklinFrom the Tax Policy Foundation: "To Raise Revenue, Tax the "Nonprofits" https://www.wsj.com/articles/to-raise-revenue-tax-the-nonprofits-exemptions-hospitals-universities-bceadf3e?st=w6nx4lvmfpix5pt
Deeper dive at https://taxfoundation.org/research/all/federal/501c3-nonprofit-organization-tax-exempt/
Reining in America’s $3.3 Trillion Tax-Exempt Economy
For over a century, lawmakers have exempted politically favored organizations and industries from the tax code. As a result, the tax-exempt nonprofit economy now comprises 15 percent of GDP, roughly equal to the fifth-largest economy in the world.