As I already alluded to this is a common criticism still being made by liberals about their own movement today. Not sure who you are trying to convince as I think it is mostly true.

Martin Luther King won out over his more radical race war baiting counterparts. Was peace and goodwill the best way to move civil rights forward? I think it probably was but it will never make everyone happy, particularly those who had nothing to gain and had already lost everything.

Also please show me the movement that is doing what the liberals could not. Things are better than they have ever been before. But that does not mean they can’t get worse or shouldn’t be better than they are.