Newly released memos, recordings and other documents have revealed that US President Richard Nixon was keen to smear his opponents by associating them with the nascent gay rights movement.

During the 1972 election campaign, Nixon aides also tried to link Democrat candidate John McGovern and his running mate Sargent Shriver to the mafia, slavery and left-wing activists.

Meanwhile, the President himself was concerned that he was not seen as a nice person.

In 1970 he wrote an eleven page memo listing all his good deeds, and expressed a hope that the press might “discover” and report on his more human side.

The new material has come into the public domain because the previously privately-owned Richard M Nixon Presidential Library and Museum was handed over on Wednesday to the National Archives.

One memo from a Nixon aide suggested trying to find TV footage of Democrats debating gay rights.

“It would make excellent footage in a union hall during the campaign,” wrote political aide Gordon Strachan, calculating that making such a link would have a negative impact on Middle American voters.

Eventually the scheming and plotting of Nixon’s aides led to his resignation.

He was forced to stand down when it was revealed he ordered an illegal cover-up of an attempt by his aides to bug the offices of the Democratic Party in Washington’s Watergate building.

Mr McGovern, now 85, told AP:

“I think it’s rather sad that at the moment of Nixon’s greatest triumph, his victory over me in ’72, he seemed to be angry and resentful and peevish.

“One would have thought that he would have been filled with joy and jubilation but apparently that isn’t the case.”