Fmr. DHS Sec. Michael Chertoff: "We’re under attack -- but it’s a domestic attack”

Michael Chertoff was Secretary of Homeland Security during George W Bush's administration. He joins Ali Velshi to discuss the future of the GOP, as well as political and national security complexities that make a 9/11-style commission trickier in “a much more political environment.” “After 9/11 everybody came together...because we knew we were under attack. We're under attack now...but it’s a domestic attacker.” The political divide this creates has beget “an allergy to the truth,” says Chertoff.