The ‘Hardball’ host is now under pressure to resign after invoking the historical comparison during an on-air conversation with Brian Williams.
In the widely shared clip, he analyses the vote tally of Mr Sanders and compares his strong early performance to the lacklustre voting numbers of Joe Biden and other moderates.
He then concludes by saying: “I was reading last night about the fall of France [to the Nazis] in the summer of 1940.
“And the general, Reynaud, calls up Churchill and says, ‘It’s over.’
“And Churchill says, ‘How can that be? You’ve got the greatest army in Europe. How can it be over?’ He said, ‘It’s over.’”
Although he fell shorting of explicitly naming them, it appears from his comments that he was comparing Mr Sanders to the Nazis.
It was seen as particularly insensitive by some, given that Sanders, who is Jewish, had most of his family killed in the Holocaust.
Mike Casca, Mr Sander’s communications director, said: “Never thought part of my job would be pleading with a national news network to stop likening the campaign of a Jewish presidential candidate whose family was wiped out by the nazis to the third reich. But here we are.”
David Sirota, who also works for Mr Sanders, also tweeted his disapproval. Mr Sirota wrote that only a few days before another American journalist, Chuck Todd, had read a passage comparing Mr Sanders’ votes to Nazi brown shirts, adding: “Bernie is Jewish and his family was killed by the Nazis. None of this is OK.”
Journalist Alex Kotch wrote: “For once, I’m not being sarcastic here. I’m dead serious. I’m really, really insulted by a major pundit on an allegedly liberal news network comparing a Jewish candidate’s overwhelming caucus victory to the French losing a battle with the Nazis. Get this lunatic off the air.”
Another Twitter user, Krishan Patel, wrote: “He should be fired immediately.”
Saturday saw Mr Sanders win the Nevada caucuses by an apparent landslide, propelling himself into solid frontrunner status among Democrats and moving his campaign one step closer to taking on Donald Trump in November.
Matthews also claimed that the Trump team is “sitting on so much opposition-research on Bernie … including his views on world affairs”. He added: “They’re going to kill him.”