CNN anchor Don Lemon abruptly ended a segment with Republican presidential candidate Vivek Ramaswamy after a tense back-and-forth about gun rights and black Americans. What happened? During an interview on "CNN This Morning," co-host Poppy Harlow asked Ramaswamy about his speech last week at the NRA convention. In that speech, Ramaswamy connected gun control laws and the campaign to oppress black Americans after the Civil War. We fought a civil war in this country to give black Americans the equal protection under the law that we failed to secure them in 1776. But then, you want to know what happened?...