Donald Trump is utterly obsessed with his hair. During the right-wing leader’s Salem, Va., rally, Trump, 78, was completely distracted when he caught a glance at the back of his head and was not pleased. “Oh s—. Look, I’m looking at the back of my head,” he told the crowd. “What the h—. I don’t like it. I look over, and now I look up there; I see I’m having a bad hair day. This is not good. I have to have a bad hair day in front of Virginia. That’s not good.” “He needs a new wig, I guess,” one X, formerly known as Twitter, user jokingly wrote below the clip. “When has he ever had a good ha…