If I had planned to speak for 13 hours when I took the Senate floor Wednesday, I would’ve worn more comfortable shoes. I started my filibuster with the words, “I rise today to begin to filibuster John Brennan’s nomination for the CIA. I will speak until I can no longer speak” — and I meant it. I wanted to sound an alarm bell from coast to coast. I wanted everybody to know that our Constitution is precious and that no American should be killed by a drone without first being charged with a crime.