The amount of people you see around you progressively beginning to think the exact same thing on a variety of subjects just confirms it. Plus, the lack of capacity to actually support their positions reinforces it. The word capitalism, for example, is not even used anymore by Portuguese politicians, except by those on the far-left (to criticize it). To defend capitalism is perceived as dangerous and yet is the what any real liberal should do. Make no mistake, there are perfectly reasonable positions and opinions that are simply banned from the mainstream language.