In our current moment of political and moral crisis, Americans are facing "an all-out attack on who we even claim we are trying to be," Rev. Dr. William J. Barber II tells Ali Velshi. As Americans, we have a moral, even spiritual duty to stand up and fight for our own rights and for those of our neighbors and especially the most vulnerable among us. Ali shares his Independence Day thoughts on how we can all work towards a more perfect union and finish what the founder began. "All of us have to