The meaning of "Anitifa" in the United States is a little misleading.

"Antifa" isn't commonly used to designate just anybody who opposes Fascism or who fought against it World War II.

When the right talks about "Antifa," they mean that teeny-tiny number of political thugs prepared to use violence not just against actual Fascism, but specifically and more often to advance communism or, possibly more often, anarchism. "Antifa" presumably consider FDR and the Clintons "Fascists." (I can remember when "Antifa's" predecessors, like the Weathermen, were stridently denouncing Johnson and Nixon as "Fascists.")

In right-wing fantasy, "Antifa" is all over the place.

But as so often has been said, there is no coordinated "Antifa" organization. Just a tiny, tiny, disorganized network of potentially dangerous nuts.