“What did the President know, and when did he know it?”

The question has preoccupied our nation ever since the Senate began investigating the Watergate scandal.

For more than a year, as evidence of illegal White House activities has mounted, President Nixon has been clashing with congressional committees, special prosecutors and the federal courts. He’s refused to turn over documents and tapes, claiming “executive privilege.”

The result: a botched burglary at the Watergate apartment complex has become a major constitutional test of presidential power.

Two weeks ago, a unanimous Supreme Court ordered Nixon to turn over tapes of Oval Office conversations. Presidents can claim executive privilege, they ruled, but not even a president is above the law.

Evidence on the tapes cost Nixon the presidency.