The governor of the state then sent a letter to Congress in which he de-certified the original electors.
“The governor of the state [Hawaii] then sent a letter to Congress in which he de-certified the original electors.”
The Governor had no power to certify nor decertify. Per Article 2 of the Constitution,
only the Legislature may choose electors. Whichever the Legislature originally chose [which I assume were those for Nixon], that’s whose electoral votes were cast. And the Vice President, head of the Senate, would have chosen those. Didn’t help Nixon, though, since Mayor Daley had already fixed the election for Kennedy.