Not sure what the parent was talking about specifically, but the ACLU has fallen into the trap of pursuing partisan politics. They have leaned hard into anti-Trump rhetoric to the point that it consumes almost all of their messaging, and at the same time they have distanced themselves from ideals they once defended (in particular, they have stopped providing legal defense support for free speech court cases if they find the speech sufficiently reprehensible).

The problem I personally have with this shift is that organizations like the ACLU, FSF, and EFF are really only useful if they defend a core set of ideals rather than towing the ever-shifting partisan line. There are plenty of ways to fund Democrat/Republican causes, but strikingly few ways to fund civil liberty defense, software freedom, and the rest of the values with less mind share.