CBS anchorman Walter Cronkite was called “the most trusted man in America” back in his heyday of the ’60s and early ’70s. His announced opposition to the Vietnam War was influential because it seemed at the time that a thoughtful, unbiased, reasonable man had come to an obvious conclusion after much soul-searching.

It turns out, though, that Uncle Walter wasn’t as unbiased as we thought. In fact, he was apparently a lefty tool all along, or at least had been for some time:

Legendary CBS News anchor Walter Cronkite allegedly collaborated with anti-Vietnam War activists in the 1960s, going so far as to offer advice on how to raise the public profile of protests and even pledging CBS News resources to help pull off events, according to FBI documents obtained by Yahoo! News.

The documents, obtained through a Freedom of Information Act request, say that in November 1969, Cronkite encouraged students at Rollins College in Winter Park, Fla., to invite Maine Sen. Edmund Muskie to address a protest they were planning near Cape Kennedy (now known as Cape Canaveral).

The story uses the word “allegedly,” which gives Walter some cover. But the proof is in the document. There ain’t no allegedly about it.