How has the Paris attack shifted the U.S. fight against ISIS, refugee policy and the 2016 campaign?

One week after the terror attacks in Paris left 130 people dead, the United States and global community have intensified the resolve to defeat ISIS and prevent future attacks. In state houses across the country and in the U.S. House of Representatives, the conversation has shifted to refugee policy and preventing all Syrian refugees from entering the country until security measures can be stepped up. 2016 presidential candidates are weighing in as well with Republican frontrunner Donald Trump calling for a national database to track Muslims. Gwen Ifill explores how the attack shifted U.S. foreign policy and the race for the White House with Pete Williams of NBC News, Alexis Simendinger of Real Clear Politics, Ed O'Keefe of The Washington Post and Susan Davis of NPR.