Brian Stelter has the story: Elon Musk has called MSNBC “the utter scum of the Earth.” He has said the channel “peddles puerile propaganda.” Just a few days ago he said, “MSNBC is going down.” And now he is posting memes about buying the channel. Conventional wisdom holds that Musk — the world’s richest man and key Donald Trump ally — and his friends are just joking. But Musk’s posts are adding to the anxiety that MSNBC staffers are feeling about the reelection of Donald Trump and the recently announced spinoff of Comcast’s cable channels. I spent Sunday on the phone with sources to gauge what might be going on. I learned that more than one benevolent billionaire with liberal bonafides has already reached out to acquaintances at MSNBC to express interest in buying the cable channel. The inbound interest was reassuring, one of the sources said, since it showed that oppositional figures like Musk (who famously bought Twitter to blow it up) would not be the only potential suitors. But contrary to claims that Trump’s allies are posting on X, Comcast has not put a “for sale” sign on MSNBC’s door. If Comcast chief Brian Roberts really wanted to sell the liberal cable news channel, he could have done that already. Instead, he is moving MSNBC and a half dozen other cable channels into “SpinCo,” a pure-play cable programming company. The hope is that spinning off the pressured-but-profitable channels will boost shares of both Comcast and “SpinCo.” Comcast says the transaction…