The ACLU is only one segment, just as there are various segments in the other side. There are historical examples of liberals supporting restrictions on free speech going back decades (again, only some segments). For example, forced public sector union dues, various speakers being booed or intimidated to not speak, even school curriculum/speech (firearm education and images). Then there are segments that don't support those groups being able to speak, such as the SPLC.

So I don't really see much difference from historical examples. There are subgroups in both sides that may take opposing stances. To be fair, the historical versions of any party no longer exist. They evolve, that's what they do.