You think Antifa are "anyone they don't like?" Clearly you have not been paying attention. They are well-organized, well-funded, domestic anarchists who are using fear, rioting, murder and political blackmail to try to overthrow our form of government and install a socialist regime based on Marxist principles. Domestic terrorists indeed. Now the Patriot Act did offer a definition of what a Domestic Terrorist is, however this has not yet been challenged in court and is not likely to stand up. I can guarantee you that the Trump administration has traced funding for Antifa to organizations outside the US - likely Soros funded organizations located outside the US to avoid scrutiny by the IRS - and THIS ALONE defines these groups as externally funded and qualifies they as International Terrorist organizations.