Everybody wants to see justice done in the Trayvon Martin case, and almost everybody acts as if they already know what that is. Never mind the Rev. Al Sharpton, activist and crusading journalist all in one. Nor his MSNBC colleague Lawrence O'Donnell, who recently announced he'd decided to forgo wearing a hoodie on TV to look more like a prosecutor. Here's GOP presidential candidate Rick Santorum on "Face the Nation," assessing shooter George Zimmerman's mental health. "Someone has a very sick mind who would pursue someone like this," Santorum said. "This is clearly a heinous act. You know, there are...