Pundits have offered various explanations for the blackout. Across the blogosphere, LaRouche's media snubbing is ascribed to reportorial laziness and a fierce love of the status quo. There's certainly some truth in that. But it'd be a helluvalot truer without the LaRouchean spin.
Lyndon LaRouche, like the Republican front-runners, has deeply held convictions that most would consider extreme. Difference is, the extreme convictions of the other candidates are easy to talk about. Everybody's got an opinion on Young Earth creationism, 'cuz it's occurred to everybody over the age of four that there's an Earth and it must have come from somewhere. A reporter can file a story from that particular front in the culture war and not have to expend thousands of words on dense exposition.
Journalists know they can't make LaRouche's pet causes intelligible; that the most they can do is portray Lyndon LaRouche as an extremely popular person with a few weird ideas. And I suspect they also know that it would be extremely irresponsible to help America to elect Lyndon LaRouche without first wrestling with those ideas. Which is true. So they ignore him, or dismiss him as a fringe candidate. Which he might be, even if most of us don't know enough about diplomacy, monetary policy, or the vagaries of the education system to tell.
Some may argue that if we start treating candidates like LaRouche seriously, we'll have to give equal time to nutjobs like Ron Paul, but that's simply not the case.
Ron Paul wants to get rid of the Internal Revenue Service and to pull us out of the United Nations. He believes in a fantasy world where corporations can be trusted to do the right thing because good behavior is good business, and he has the white supremacist vote locked up. That's crazy! Even though the LaRouche and Paul platforms share many planks—both oppose abortion, the Fed, and environmentalist causes, among other similarities—one of these men is obviously a crank, and the other one is a political genius. One absolutely deserves your attention, and the other does not.