We have been living in an age of identity politics — I am Christian, I am black, I am white, I am gay, I am a woman and so on. This kind of politics has proved itself very powerful and has helped to produce many good things. The Civil Rights movement produced real change — not enough, plainly, but real. The women's movement produced real change — again, not enough, but real. Who would have imagined 20 years ago that gay marriage would be legal?