Here’s an interesting anecdote bearing on the dangers of unchecked surveillance powers. And it comes from a somewhat unlikely source: the Heritage Foundation’s Lee Edwards, a historian of the conservative movement and biographer of Barry Goldwater.

Edwards tells the story of the FBI, at Lyndon Johnson’s request, placing bugs on Barry Goldwater’s campaign plane:

The bureau’s illegal surveillance was confirmed by Robert Mardian, when he was an assistant attorney general in Nixon’s first term. During a two-hour conversation with J. Edgar Hoover in early 1971, Mardian asked about the procedures of electronic surveillance. To Mardian’s amazement, Hoover revealed that in 1964 the FBI, on orders from the Oval Office, had bugged the Goldwater plane. Asked to explain the blatantly illegal action, Hoover said, “You do what the president of the United States orders you to do.”

Here’s another such anecdote from another conservative, federal judge Laurence Silberman, by way of Robert Novak. As a deputy attorney general in 1974, when the House Judicary Committee asked him to review secret files kept by J. Edgar Hoover. Silberman discovered a cache of “nasty bits of information on various political figures — some still active.” According to Silberman, “Lyndon Johnson was the most demanding” when it came to requisitioning FBI political intelligence. In 1964, after D.C. police arrested LBJ aide Walter Jenkins for homosexual conduct, special assistant to the president Bill Moyers ordered Hoover to find something similar on Barry Goldwater’s campaign staff.

Conservatives may get a kick out of Moyers’ discomfort at having his gutter tactics exposed (“I was very young. How will I explain this to my children?”), but there’s a larger point here beyond schadenfreude. When presidents get to exercise unchecked power in the national interest, they tend to have a hard time telling the difference between the national interest and their own political fortunes. The post-Watergate reformers made some mistakes, but many of their reforms — FISA among them — were aimed at changing the dynamic described by Mardian: “You do what the President orders you to do.”

Unfortunately, the Bush administration’s legal theories threaten to shift it back.