There are several reasons for this, IMHO. First, newsrooms are filled much more with college graduates than used to be the case, and their sources of education tend to be overwhelmingly liberal. Second, it is a central tenet of liberal dogma that liberals are smarter than conservatives, which colors any attempt at political diversity in hiring and promotion (as it does on campus as well). And third, there is the seduction of power. Young journalists get into the business for the admirable if somewhat callow reasons of "making a difference" and "changing the world." But the environment is more cloistered than it used to be and that tends to shield those young people from learning better in the way they might in, say, the construction industry or the military. A reporter committed to becoming an agent of change is a reporter impossibly compromised. Surrounded by similarly motivated colleagues there is no corrective, and the tendency toward groupthink becomes simply a matter of career survival.
Goldberg has said it elsewhere and I think he's correct - they don't even know they're doing it. In fact, they bristle at the mere suggestion. Fish don't notice the water.
Couldn’t agree more, you nailed it.
My granddaughter wants to major in journalism, she’s a very good writer already. We’ve had many discussions about this very thing and fortunately her parents are good conservatives, I’d like to believe she’ll buck the odds.