Never before published photographs and declassified White House tapes illuminate President Nixon's strange early morning visit with student protesters at the Lincoln Memorial on May 9, 1970.Never before published photographs and declassified White House tapes illuminate President Nixon's strange early morning visit with student protesters at the Lincoln Memorial on May 9, 1970.Never before published photographs and declassified White House tapes illuminate President Nixon's strange early morning visit with student protesters at the Lincoln Memorial on May 9, 1970.