The new British prime minister, Theresa May, wants to move her party (the Conservatives) to the political center. But the center ground in politics can be a dangerous place, especially if it is not clear where that center actually lies today. It could be shifting — and fast.

For example, the British leader pitched her remarks to "ordinary working class people." But a recent think tank survey — in March of this year — showed that 71 percent of the British people now define themselves as middle class. In all probability most people are becoming fed up with these class generalizations and categories altogether.

Another so-called center used to be the mid-way point between the old 20th century ideologies of capitalism and socialism, the idea being that free but regulated market capitalists spreading their capital around on one side, and socialists happy to work with markets on the other side could somehow all meet in the middle in common cause.