On February 7, 2020, during a panel discussion following a Democratic Party presidential candidate debate in New Hampshire, Matthews referenced Bernie Sanders' praise for aspects of Fidel Castro's Cuba, saying "[Had] Castro and the Reds had won the Cold War, there [would have been] executions in Central Park and I might have been one of the ones getting executed and certain other people would be there cheering, OK? So I have a problem with people [who] took the other side." His remarks were mocked by left-wing commentators.
In February 2020, political journalist Laura Bassett alleged that, prior to appearing on his program in October 2016, to comment on sexual assault allegations against then candidate Donald Trump, Matthews made inappropriate remarks about Bassett's makeup, clothing, and dating life. As she was having her television studio makeup applied, Matthews purportedly asked her: "Why haven't I fallen in love with you yet?" Bassett claims that when she laughed nervously and said nothing, Matthews followed up to the makeup artist with: "Keep putting makeup on her, I'll fall in love with her." In 2017, Bassett had previously published a text about the incident, which did not identify Matthews by name.
On February 22, 2020, commenting on the 2020 Nevada Democratic caucuses, Matthews invoked Winston Churchill's feeling of disbelief following the fall of France to the Nazis in 1940 as a metaphor for the feeling of disbelief experienced by establishment figures in the Democratic Party to Bernie Sanders' victory in the state. As members of Sanders's family were killed by the Nazis during the Holocaust, his comparison was viewed as insensitive and prompted widespread negative reactions on Twitter calling for him to be removed from MSNBC. Amid mounting criticism, Matthews issued an on-air apology to Sanders and his supporters on February 24. Sanders did not directly respond to the remarks, but instead urged the general public to focus its energies on the emerging COVID-19 pandemic.