Christians are portrayed more unfavorably than favorably in the national media. Local media is more often favorable, though. Or at least less unfavorable.
TV is all about "me." It's not very often about "you," and only sometimes is about "us." There isn't any "him." Christianity is all about "him," very often about "us," sometimes about "you," but rarely about "me," at least not publicly.
TV, news especially in almost all markets, likes flashy, glaring, obvious, rapidfire, quick, base, and immediate, and it appeals to the lowest common denominator, for the greatest portion.
Christianity doesn't fit into the entertainment box TV wants to fit things in. It's way bigger, way wider, way deeper. You have to think a lot, not just sit down and be entertained. Christian things aren't settled in twominute packages with an ENG crew and an editor. [Maybe if we could package them up like that for the news stations, they'd begin to use them....
] Some things you can only begin to understand through trials and experiences and learning, which isn't what a lot of people want to do.
We're held up to a higher standard, as it should be. So when one of us makes a mistake, the difference is more glaring and obvious, so it gets pointed out more often than someone who hasn't claimed to have a higher standard to reach. TV news likes glaring and obvious, not subtleties, unless you're talking about "pushing the envelope," which they seem to delight in.
Because of the nature of news cycles and news itself, Christians often don't get a chance to refute any little side comment that someone on the outside makes [like saying James Dobson is a right wing wacko,

I tried to let it slide but I couldn't, I know it had to be a mistake. You can factor in how "on the outside" applies here on your own

I've never seen Dobson labeled a rightwing wacko by ANYBODY].
The opposition can say whatever they want, and it sticks in the mind of the viewer; we can say what we want, but for us to prove the statements wrong takes time and effort and evidence that what we say is true. TV isn't interested in time and effort, they want right now sound bytes, and by the time enough time passes that our claims would be proven, the media is on to another hot story.
Blanket statements like "right wing wackos" and "fundamentalists" and other charged terms get bandied about, and they stick WAY too often. It's like they say, you always hear "devout Christian senator" you never hear "lousy, rotten scoundrel heathen humanist senator" or "liberal communist senator."
As for the radio and newspapers and local television stations (outside the news departments), they answer to more local, less homogenized, genericized audiences. They have actual experience living near and with the people they cover, so they are less biased against Christians, or at least more willing to present a Christian perspective without imposing their own perspective.
Whew. "Christians and media" is one of my hotbutton issues...