From Dawn to Decadence: 1500 to The Present, notes that the European intellectuals and politicians threw political vocabulary into disorder by morphing liberalism into socialism. Here’s an excerpt from Part IV, Section I, “The Great Illusion,” of Barzun’s book:
What Shaw and all the other publicists who agitated the social question helped to precipitate was the onset of the Great Switch. It was the pressure of Socialist ideas, and mainly the Reformed groups in parliaments and the Fabian outside, that brought it about. By Great Switch I mean the reversal of Liberalism into its opposite. It began quietly in the 1880s in Germany after Bismarck "stole the Socialists' thunder"—as observers put it—by enacting old-age pensions and other social legislation. By the turn of the century Liberal opinion generally had come to see the necessity on all counts, economic, social, and political, to pass laws in aid of the many—old or sick or unemployed—who could no longer provide for themselves. Ten years into the century, the Lloyd George budget started England on the road to the Welfare State.
Liberalism triumphed on the principle that the best government is that which governs least; now for all the western nations political wisdom has recast this ideal of liberty into liberality. The shift has thrown the vocabulary into disorder. In the United States, where Liberals are people who favor regulation, entitlements, and every kind of protection, the Republican party, who call themselves Conservatives, campaign for less government like the old Liberals reared on Adam Smith; they oppose as many social programs as they dare. In France, traditionally a much-governed country, liberal retains its economic meaning of free markets, and is only part of the name of one small semi-conservative party; Left and Right suffice to separate the main tendencies. In England also, the new Liberal party numbers very few. Conservative and Labor designate the parties that elsewhere are known as Conservatives in opposition to Social Democrats. The political reality, the actual character of the state, does not correspond to any of these labels. It is on the contrary a thorough mixture of purposes and former isms that earlier would have seemed incompatible. Nowadays, a sensible voter should call himself a Liberal Conservative Socialist, regardless of the election returns. Changes of party mean only a little more or a little less of each tendency, depending on the matter under consideration.