They have been, at multiple times, ruled by Socialists, or governed by socialist policies. Your defense is only that it wasn't "real" socialism. At the moment, even if the governments are explicitly Democratic Socialists, they are effectively Fabian Socialists, supported by many Leftist populists.

The UK is a good example of a country that has been ruled by Fabian Socialists for around a hundred years or so, and has been more and less aggressive with it's Socialism in all but name.