When a liberal politician changes his mind, particularly when he journeys to an even more liberal position, you can count on his fellow travelers in the media to refer to such a fortuitous happenstance as an “evolution.” A case study of this phenomenon is to be found on the front page of today’s Boston Globe. The story promises to look into Barack Obama’s changing positions on Iraq, or, as the headline puts it, “Obama stance on Iraq shows evolving view.” The Globe reports: