rubio out talking with students and veterans, but ted cruz picking up a big endorsement. let's talk about this feud between marco rubio and ted cruz. this has been going on ever since after the last debate. you've seen them go after each other on topics like national security and immigration. that seems to be where marco rubio is escalating his language and sharpening his attack line against ted cruz. this is what he said when i asked him about the feud between the two. >> senator cruz and others have been given a choice between isolationism or the defense of our country and he's chosen isolationism. whether it's weakening intelligence gathering or voting against the defense bills or a budget that reduces our defense spending. these are facts. >> reporter: this coming on the heels of that interview on "morning joe" talking about