NBC News Signal - January 31st, 2019

26:57

It’s cold outside…that doesn’t mean global warming isn’t real. The playbook for running in 2020 when you’re a relative unknown. How President Trump’s approval rating stacks up against past presidents at the same point in their presidencies. The evolving description of the proposed physical barrier between the U.S. and Mexico. And, should A.I. be regulated? Experts debate, and then switch sides.