MSNBC weekend host Melissa Harris-Perry lined up a panel of alleged comedians to mock the Christmas picture Mitt Romney posted on Twitter. In a segment with the on-screen question "What's So Funny About 2013?" Harris-Perry announced: “This is the Romney family. And, of course, there on Governor Romney’s knee is his adopted grandson, who is an African-American, an adopted African-American child, Kieran Romney.†To which comedian and actress Pia Glenn sang the old Sesame Street ditty “One of these things is not like the others, one of these things just isn’t the same … “And that little baby, front and...