that's interesting. >> well, here's on today's endorsement, sherrod brown endorsing hillary clinton, some people found that surprising because you know, sherrod brown ideologically and voting records he was more similar to bernie sanders than hillary clinton. of course, there's a lot of criteria that go into this selection process of endorsements. what are they other than ideologically affinity? >> well, elites have a lot of reasons as you're suggesting ha they might want to jump on the bandwagon with one candidate or another. those range you know from wanting to be on the winning team to hoping to play a role either in the campaign or perhaps in the administration. to just wanting to join the process and generate media coverage. we as political scientists don't know the a lot about the individual reasons that each different political elite might make those choices but what we're always talking to you guys about is sort of the average collective state of the endorsement pool. >> here's where it gets interesting. on the democratic side, a pretty clear front runner hillary clinton both

senator sherrod brown of ohio, one of the most prominent progressives in the u.s. senate, he announced he was backing her. senator brown joins us now. thank you so much for joining us on this big news day. >> good to be with you, thank. >> what was in your thinking in making this decision between -- i don't know if you're in the middle of these two, but you're pretty close to probably senator sanders, but also, you're a pretty regular democrat, too. and he's not a democrat. he's a socialist. how did your thinking come to be today in this endorsement? >> well, first, i've been really pleased, as progressives has been and democrats are. and i think the country is in many ways, too, to contrast the democratic debates with republican debates, in the year. and particularly bernie sanders and hillary clinton, when they sometimes disagree and they don't often, but when they disagree, they've done it respectfully and done it with showing respect to the voters. you look at the republican debates and they border sometimes on discussions of race and xenophobia and no respect f

senator sherrod brown, thank you. >> joining us is our msnbc contributor and co-host of "ring of fire radio show." you were there in vegas. what was your impression? >> well, you know, the impression was a little bit sort of i guess dictated by the fact i was surrounded by media. i got to say that i think hillary clinton, i think she put out the fire in terms of the establishment concern about her and closed the door on any opportunity that joe biden might have had. but i think what was really striking was that bernie sanders was sitting up there and he was going toe to toe. they weren't necessarily going at each other. but there was a sense, i think, for a lot of people who didn't know who bernie sanders was that some type of democratic socialist was w. some type of bogeyman. i think that he really succeeded in i guess phase one of introduing himself to the country. i don't think there was a lot of democratic voters who knew much about him. i think he was very effective in showing a clear agenda. i think he's got some work to do in terms of differentiating himself from hillary clinto