Walter Cronkite, Eric Severied, et al were just as liberal/progressive as the big news media figures are now. The public just didn't have anything to compare their reports with then. Remember the love fest for the Kennedy family. JFK didn't look good for reelection, so we got a neverending story about the "young" president and his happy family. Then he got killed and we got Johnson with a public in sympathy mode for The Great Society, and a deeper involvement in Vietnam. It used to be that you got hired as a reporter because you had life experience, and knew how to get the "story". Now you get hired because your socialist professor writes a glowing recommendation for you and how you want to "change the world".