Senator Lieberman’s threat to filibuster the health-care bill isn’t a betrayal of the Democratic Party, says Meghan McCain—it’s a sign of courage. And we need more of it. BY MEGHAN MCCAIN A few weeks ago, I gave a speech at the University of Massachusetts Amherst and one of the questions I was asked was: Aside from your father, who are your favorite senators and politicians? Without hesitation, I said that I admire South Carolina Senator Lindsey Graham and Connecticut’s Joe Lieberman. Now before my fellow Republicans start panicking at my fondness for two independent, moderate, and dare I say maverick...