sanders. >>> plus, he's the man tasked with making sure the senate's trial is fair. we'll look at chief justice john roberts' role in impeachment. >> judges and justices are servants of the law, not the other way around. judges are like umpires. umpires don't make the rules, they apply them. the role of an umpire and a judge is critical. they make sure everybody plays by the rules, but it is a limited role. nobody ever went to a ball game to see the umpire. >>> and the 2020 campaign trail is back in business today across four states, and one of those candidates, senator bernie sanders, is getting a warm welcome back. take a look at these headlines just from the last 24 hours or so. the "new york times," why bernie sanders is tough to beat. "politico," democratic insiders say bernie could win the nomination. "wall street journal," don't count bernie out, and that's just a few of the headlines we've seen. they all tout his resiliency and impressive rebound from a heart attack two months ago, and also his consistent slow climb in the polls. but they also emphasize a concern that his quiet rise is being overloo