Actor Sam Rockwell talks about his new movie "Three Billboards Outside Ebbing, Missouri," and the preparation he's done to play George W. Bush in Adam McKay's forthcoming Dick Cheney biopic; Jon Robin Baitz's play "Vicuña," about a Trumpian presidential candidate, premiered in L.A. before the 2016 election. Now it's taken on new resonance with a staging in Washington, DC.