James Fallows talks about how politicians want to talk about their agenda, but the press only wants to hear about the freak show:

The obvious complaint, easily dismissed by reporters, is that press coverage is biased against or "too tough on" this or that candidate. Reporters tell themselves: Hey, we're tough on everybody. You're not strong enough to take it, maybe you should find a different line of work.

The more heartfelt and bitter complaint is about the way press coverage seems biased not against any particular candidate but against the entire process of politics, in the sense that politics includes the public effort to resolve difficult issues. (Medical care, climate change, banking crises, military priorities, etc.) For twenty years I have heard this from frustrated politicians -- Gary Hart, Newt Gingrich, Jimmy Carter, Dick Gephardt, Bill Clinton, they may not share a lot of views but they are as one in this frustration. What galls all of them is the way that the incentives created by most coverage bring out the very worst in most politicians, and discourage them from even bothering to try the harder, more "responsible" path. No one says that press incentives turn potential Abraham Lincolns into real-world Tom DeLays. But the incentives push in that direction rather than the reverse.

What's driving this, I think, are the dual desires to be "tough" and to be "objective." In particular, being objective is thought to preclude being tough about public policy because that would entail picking sides in ideology-inflicted arguments. And people didn't get into this business in order to provide softball coverage. So instead you ask tough questions about process or about trivia, even though there's little evidence that these are the subjects about which people want to hear.