http://www.nytimes.com/2007/02/12/washington/12history.html?_r=1&oref=slogin&pagewanted=printFebruary 12, 2007
A Historic Moment if Cheney Testifies Live, as Expected
By DAVID JOHNSTON
WASHINGTON, Feb. 11 — If he testifies as expected, Dick Cheney would be the first sitting vice president, at least in modern times, to appear as a witness in a criminal trial. And if he testifies in court, he may also be the first to give live testimony in defense of a subordinate’s actions on his behalf, legal historians said.
Mr. Cheney’s testimony as a courtroom witness for his former chief of staff, I. Lewis Libby Jr., would break with one of the closest historical parallels, when former President Ronald Reagan testified in 1990 via videotape as a defense witness in the trial of his former national security adviser, John M. Poindexter.
The Reagan videotape offered an insight into the unpredictability of criminal trials. His appearance seemed to have little direct impact on the trial, but it created a permanent historical record of his failing memory, which would have been preserved through a printed transcript had he appeared as a live witness but would not have caused the same impact as the widely broadcast videotape.
Courts have traditionally shown great deference to high-ranking executive branch officials, requiring them to testify only when they are thought likely to provide crucial testimony that cannot be obtained elsewhere through documents or other witnesses..............