More to the point, why should potential voters expect Matthews to treat the candidates' views fairly?By engaging in this sort of intemperate rhetoric, Matthews has effectively disqualified himself as an "honest broker" for this coming debate.
NBC needs to replace him as a debate moderator immediately. The job - by definition - requires an attempt to display objectivity going into an event.
Yes, the distinction between "objective journalist" and "opinion-maker" in recent years has been blurred to the point where they're nearly indistinguishable. But Matthews' comments obliterated any possible distinction.
Earlier this year, the Democratic presidential candidates refused to participate in a debate on Fox News on the grounds that the channel was "biased." That's baloney, of course - certainly the debate wasn't going to be moderated by Fox's prime-time opinion hosts.