What exactly does "Liberal" mean really?
Generally people don't mean classical liberalism specifically, but contemporary social Liberalism.
Generally they are the default ideas - or among a lot of the main assumptions - of lots of workers in our society and so for most people, radicalization means breaking with a lot of these ideas which they had taken for granted. I think that's also why these ideas get jumped on pretty quickly by comrades because they are the ones we most often have to argue against in unions or activist movements. These ideas are usually presented as abstract values and in practice often hold back movements by demanding adherence to abstract ideals that our opponents never live up to: so "turn the other cheek" and "play the game and try and change the system from within" are probably the most common liberal things you might hear in unions and social movements. Sometimes these ideas are part of a more organized political strategy, but often they are just reflected by people in movements; IMO we should not see them as "the enemy" rather we should see it as mixed consiousness and try and win people to a better understanding and more effective tactics if not to revolutionary politics outright.
Then there's also official Liberalism which would be historically things like "Guns and Butter" sort of policies of social peace in exchange for popular support for the Ruling Class. This really is more explicitly counter-posed to class struggle and the independant interests of workers and is an "opposing ideology".
