I've been confused by the ads put out by the Marshall Tuck supporters, so I searched on ACLU and Tony Thurmond. I found this article from the Sentinel News Service saying that the ACLU of Northern California strongly condemns the use of their name in ads against Tony Thurmond: https://lasentinel.net/aclu-of-north...-thurmond.html
Also this letter from the executive director of the ACLU Foundation of Northern California.
See also the piece from the Berkeley Daily Planet: https://www.berkeleydailyplanet.com/...-Tuck-Campaign