Why was Richard Nixon's legacy preserved at his presidential library despite his resignation, while Trump closed the JFK Library?

Richard Nixon, the only president forced to resign due to criminal misconduct in the Oval Office, continues to be memorialized at his presidential library, which Donald Trump did not close down. Despite facing potential impeachment, removal from office, and possible federal prosecution, Nixon's legacy was protected when his vice president, Gerald Ford, pardoned him one month after his resignation. This criminally pardoned president's commemorative institution remains operational, contrasting sharply with Trump's decision to close the JFK Library. This distinction highlights the selective approach to preserving presidential legacies in modern American politics.