Why was President Johnson so eager to distract from and indirectly interfere with the live TV coverage of the 1966 Fulbright Hearings on Vietnam?

What was the “metallic poetry” of Edward R. Murrow’s World War II radio reports from London, how did his “Radulovich” and “Harvest of Shame” TV programs engage in advocacy journalism, which political and commercial pressures on Alcoa would eventually terminate its corporate sponsorship of See It Now, and why was President Johnson so eager to distract from and indirectly interfere with the live TV coverage of the 1966 Fulbright Hearings on Vietnam?