2017: the ACLU defends Milo Yiannopoulos' right to advertise his new book. They file an amicus brief in the Supreme Court supporting a Tea Party supporter challenging a ban on wearing political insignia at polling places.
2018: the ACLU supports the NRA's First Amendment challenge to Governor Cuomo's attempt to convince NY financial institutions not to do business with the NRA.
2019: they defended a conservative student magazine which was denied funding by UCSD.
2020: they filed a brief supporting antisemitic protestors picketing a synagogue on the Sabbath. They also supported a Catholic school's religious right to make religious-based choices in hiring and firing teachers.
I'm just quoting the fruits of five minutes of research here, so I won't go on (but there's more). Is it possible that you're reacting to the radical conservative stereotyping of the ACLU rather than the actual actions of the organization?
It's very possible that I'm misinformed, but if so it was mostly from reading 'radical conservatives' like the NYT and other related reporting, along with ex-ACLU lawyers. [0]
0: https://www.nytimes.com/2021/06/06/us/aclu-free-speech.html
I think this is particularly noted as a post-2022 shift