It has been three years since Les Moonves, chairman of CBS, pronounced that the era of the “voice of God” television news anchor was over. US viewers, he said, could no longer turn to “that guy, preaching from the mountaintop” for their information.

In recent weeks, the number of authoritative voices in the US media has grown even smaller, with the death in June of Tim Russert, the host of NBC’s Meet The Press show, and the retirement this week of Robert Novak, the veteran conservative columnist and talk show regular, following the diagnosis of a brain tumour.