The FDIC could issue regulations on the issue. Broadly stated, financial institutions are vested with a public purpose that should limit their ability to discriminate against customers.
Nigel Farage and a number of other prominent conservatives were debanked by Coutts Bank (owned by NatWest)
The Financial Conduct Authority “investigated” and found no wrongdoing.
(Note that this is all occurred under a “Conservative” Government. And the UK gov’t still owns approx 40 percent of NatWest).
NatWest and Coutts executives later resigned over illegal leaking of Farage private financial information.
People need to have a backup account in a State Chartered Bank. In the UK it is more difficult, the best they can do is a credit union.