It's the urban media, not the mainstream media. There are no streams in a city, only sewer pipes.
Conservative areas of the country generally have a population density less than 800 people per square mile. It's hard to run a profitable news media business and hire top conservative talent if the employees are so dispersed, and so are the interviewees and news makers. Most news is negative and most negative events occur in the cities, not the countryside. However the internet now makes country news media possible. News production staff can work in a virtual city but live 1,000 miles apart, and produce a product of interest outside the urban communes.
Christie does have a point, RINO’s bring the attention to themselves and the media just exploits it.