No argument there.
I suspect the reluctance of the Nixon Administration to prosecute Fonda, Hayden, et al had something to do with the ability of the Left to put 500,000 people on the streets in Washington.
I suspect the Nixon administration was reluctant to prosecute these people because they knew they couldn't possibly keep a straight face in court when a defense attorney asked them to explain what meaning the word "enemy" has in Federal treason statutes in the context of a military campaign that was undertaken without meeting even the most basic formal requirements of the U.S. Constitution.