I don't watch him either. In channel surfing I've gotten tiny dribs and drabs.
He really doesn't have to say "I'm a liberal Democrat". It's the way he acts and the way he conducts his show. It's what he says, how he says it, his body language, everything. He's a fool for Democrats. He despises Bush, Cheney and Karl Rove? Why? That's easy. They got the power and kept his Dem buds out of power.
The only time he really attacks Dems is if they mess up, in his opinion, and make it easier for Repubs to win. The only Repubs he cares for are the RINO types that hurt our cause. Matthews is out of control in his personal demeanor. He is just about rabid, politically, I would say.
Someone like that doesn't need to officially announce what they are.
But I do believe that any news show, any political events show or any reporting of the news of the day done on any program, if the person doing the reporting goes thru the shenanigans you describe in your post, should be OBLIGATED to announce their leaning toward one of the other party's.
Too many people do not read the crappy innuendo correctly. Many assume the news is JUST as, say Matthews, relates it. This is wrong.
I also think the print media, aka, the NYT, if its owners had a decent desire to be honorable, would have permanently printed on its front page 'a paper with a liberal perspective , a paper that promotes democrats and their ideals.'
That or 'Goebbels is our mentor!'
lol
This, of course, will happen when pigs fly!