A "smoking gun" is extraordinarily rare evidence. Think about it: the gun has been fired, the smoke is curling from the barrel, and the Federal Bureau of Investigation can see the traces. But James Comey, dismissed as FBI director by U.S. President Donald Trump a month ago, delivered one in his Senate testimony Thursday. It may prove injurious — possibly fatal — to the political fortunes of the Trump administration.
The famous "smoking gun tape" that doomed President Richard Nixon was recorded in the Oval Office in June 1972, the week after White House operatives were arrested breaking into Democratic National Committee headquarters at the Watergate Hotel. Nixon wanted the FBI to halt its Watergate investigation. The Supreme Court ordered Nixon to give up the tape, it provided a clear-cut case of obstruction of justice, and Nixon resigned three days later, in August 1974.
The tape gave the lie to Nixon's famous protestation that "I am not a crook." He was.