You misunderstand the differences between 2000 and 2020. When Gore lost Bush v. Gore, he didn't start leaning on state officials, plotting slates of fake electors or hold a rally to put a mob on the Mall on January 6. Gore was not prosecuted because he did not commit crimes.
Nixon not being prosecuted was a political calculation. Ford, a fellow Republican, figured nothing good comes of prosecution for anyone, and probably cost himself any shot in the 1976 election with the pardon.
One fact making the Nixon pardon less dangerous is that Nixon could not run again. If Gore does what Trump did in 2000, he probably gets prosecuted. Just because he says he'll retire from the political theater doesn't mean he will. Nixon, by contrast, could not mount a comeback.