Why is the MSM ignoring the Republican Candidate for President?

Why is it that the man who has actually announced his candidacy for the Republican nomination for president does not received any press attention while potential candidates like Donald Trump are mentioned every day?

Is this the MSM doing their job? And, if so, what is their job? Is it to sensationalize the issues? Is it to avoid topics and be snarky? Whatever their job is - it is not to hold a light up to the stories of the day and to give a rational, objective analysis of the facts at hand. The entire Obama Birther issue, for example, is due to the press not doing their job in 2008.

Again, why doesn't the MSM cover the man who has ACTUALLY announced his candidacy? Gary Johnson, is the ex two-term Governor of New Mexico who wants to introduce school vouchers, thinks that Gay Marriage ought to be legal and wants to legalize marihuana. Aren't education, gay marriage and the drug war topics worthy of discussion? Aren't Johnson's opinions different than what you would expect from a Republican candidate? Surely this ex-Governor should be able to break into the news cycle.

Why are this man ignored? Is it because he doesn't fit into the established narrative? Is it that we can't have people knowing that some Republicans want to legalize drugs or gay marriage?

EDIT: When I first wrote this post an hour ago I was under the impression that Herman Cain had announced his candidacy. I edited this post and removed my comments on Herman Cain.