ACLU has been doing a lot of good things for a lot longer than most people imagine. Yes, a lot of their clients are disgusting. Communists, Nazis, unions, Klan, socialists, etc. But they've done more to uphold the Constitution than any other organization in the country. All of it? Nope. Flawlessly? Nope. They have plenty to be criticized about. Defending freedom of speech is not one of them. They've done an excellent job, and have gotten flack about it the entire time.
Historically, right leaning folks have been the ones who wanted to shred the Constitution. Especially the first couple of Amendments. Oh, I admit they get flack for "separation of church and state", much of it deserved but not all of it. Even most Rightists don't want to bring Handmaiden's Tale to real life. The Right still leads efforts to shred due process, search and seizure, etc. Previously they have repeatedly tried to shred freedom of speech and assembly. Often with great success.
These days, it seems like Leftists have taken the banner of anti-constitutionalism from the Rightists. Open hostility to freedom of speech is probably more chilling than even the historical Rightist attacks on freedom of speech. Rightist attacks on freedom of speech were wide ranging. Obscenity, socialism, anti-war, communism, etc. But they still had a theme. Certain Leftist groups have hostility towards the entire concept of Free Speech.
There's a reason why I still donate to the ACLU. Perfect or not, there's no one else on either side with the same commitment to free speech.