He was a genius and accomplished a lot as President. He stopped the Vietnam war, opened China to trade, oversaw détente with the Soviet Union and China, presided over the moon landing, began the war on cancer, and started the EPA.

Not that everything he did was appropriate or entirely legal, but in retrospect, modern Presidents have done worse. HUAC in particular always bugged me, but there is cause to think communist sympathizers had indeed infiltrated the US.

Nixon was the last great Republican. Even Clinton regularly sought his advice.