New York (CNN Business) A version of this article first appeared in the "Reliable Sources" newsletter.

Bernie Sanders' big win in Nevada over the weekend highlighted the hostility between his campaign and MSNBC, the network with a progressive brand but an establishment bent.

The campaign continued to criticize the network over the weekend — in response to highly controversial remarks by Chris Matthews and others. One MSNBC regular, Anand Giridharadas, called out Matthews on the air and said "something is happening in America right now that actually does not fit our mental models. It certainly doesn't fit the mental models of a lot of people on TV."

So I'm wondering: Is this the big media story of the 2020 race?

In 2016, all roads led to Trump, who frequently sparred with Fox News despite all of the natural overlaps between the Fox audience and the Trump base. Something similar, though not the same, is happening now with Sanders and MSNBC. Page Six reported Friday night that Sanders loudly criticized NBC and MSNBC officials before last week's Dem debate. According to the story , Sanders approached MSNBC president Phil Griffin and said "Phil, your network has not been playing a fair role in this campaign. I am upset. Is anything going to change?"

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