The sense of "liberalism" here is the academic and historical one: it's a broad term for an ideology with a commitment to the "free market" as the primary engine of social regulation. The word as it's used in popular discourse (especially in )--as a contrast to "conservative"--is the newer and less standard definition. Mainstream political views in most of the world are all liberal: both the Republican and Democratic parties in the US believe in things like free trade, the invisible hand of the market, and so on. Communism is an illiberal tradition in the sense that it rejects that broad consensus.