18 U.S. Code § 2331 Section 5 defines domestic terrorism as activities that:

A) involve acts dangerous to human life that are a violation of the criminal laws of the United States or of any State;

B) appear to be intended—

i) to intimidate or coerce a civilian population;

ii) to influence the policy of a government by intimidation or coercion; or

iii) to affect the conduct of a government by mass destruction, assassination, or kidnapping; and

C) occur primarily within the territorial jurisdiction of the United States.

In his funding of many groups and protests Soros falls into many of these definitions. He funded protests of Donald Trump in Chicago and San Jose, the former leading to a shutdown of a rally and the latter to harm of many. For lack of space I cannot go further