he commented in all the sort of harsh fighting between trump and carson, and effectively talked about all the infighting in the race. have a listen. >> i don't think there's a line where we all wait and just hand the presidency off to each other because you've paid your dues. this is an important moment in american history, but i'm not running against jeb bush. i'm not running against ben carson. i'm not running against ted cruz. i'm running for president. >> so, lisa, that's nice. that is the nice thing to say, and it sounds nice, but we all know how politics really works, and the tough slugging really works. do you think he can stick to this strategy? >> well, and you're absolutely right. look, politics is a bare-knuckled industry, but i do think this is one of the reasons why people are drawn to marco rubio. he is such a great speaker. and i do believe a lot of republicans would like to see a little less infighting and more of the focus on hillary clinton. but we're also seeing this on the left with barbs traded between bernie sanders and hillary clinton. so, i think this is the nature of the business.