I think that the press thought that Trump couldn't win, that Clinton was a done deal. So no harm making a few bucks along the way, getting better ratings by featuring him so much.
Now they are trying to dig themselves out by reverting to the same tired liberal playbook. "OMG, we're VICTIMS!"
Suddenly, they want to hold the president to account and do real journalism.
Sorry, it just comes across as partisan because their favorite didn't win. If they'd done it when their guy was in office I'd be more impressed, but it seems like an excuse to just ramp up their partisan reporting with added victim-hood status thrown in, because that is what their crowd values.
TIP: watch PBS news - it's refreshing. No shouting and people take their turn to add to the conversation. How a discussion is supposed to be, not the Jerry Springer show that CNN too often dumps on us.