That is indeed an interesting observation but I think the major factors which have crippled political reporting in this country was first Watergate and secondly the political biases present in our journalism schools. The former because the work of Woodward and Bernstein made a number of people think they could improve the world by becoming reporters. Not report on it, but improve it. Such people were already geared up to become missionaries of their idea of the good were then incubated in the Liberal viewpoint present in most schools of journalism. In addition, most of their role models in the media were Liberals (look no further than the major networks).
Most of the Conservatives and Libertarians I met in college came out of the sciences, engineering, and political science. I never met a Conservative journalism student and the student newspaper at my college was dominated by Libs.