On Tuesday I spent a good part of the day at the Tenement Museum, on New York’s Lower East Side.  I was there to meet with the museum’s new president, Kevin Jennings, and to tour their new Under One Roof exhibit with Annie Polland, the EVP for Programs and Interpretation.  An affiliate historic site of the National Trust, the Tenement Museum tells the full American story about how many have come together to make our nation today. Which brings me to the so-called War on Christmas. The day I arrived, Kevin had just published an op-ed in Newsweek entitled “A War on Christmas?  What Christmas Are You Talking About?”  Early in the piece he asks the key question: “In recent years, a new holiday tradition seems to have emerged in America. From pundits to Presidents, the airwaves fill each December with people decrying the so-called “War on Christmas.” As a historian and museum President, I find myself wanting to ask “War on whose Christmas?” Those bemoaning the “War on Christmas” harken back to a mythical …