Nixon had to resign or face certain conviction in the Senate after impeachment, just because the burglars he sent to tap the phones in the D.C headquarters of the Democratic National Committee got caught. Senator Barry Goldwater, a reactionary as close to a fascist as one can get without being one, personally delivered the news to Nixon in the White House that the jig was up, if he didn't resign, impeachment in the House and conviction in the Senate (requiring 67 votes, which would include Republican Senators) was certain.
But Nixon's crimes look like mere peccadilloes compared to Trump's.
Trump sent a violent mob to invade the Capitol to prevent the certification of Biden, the Democratic presidential candidate, as winner of the 2020 presidential election. He refused for several hours to call off the mob, ignoring the entreaties of Congresspeople telephoning him and of his daughter Ivanka in the White House. When, hours later, he realized his coup attempt had failed, he finally messages the mob to depart, which they instantly did- proving he controlled them.
He was recorded on a phone call to the state of Georgia's Secretary of State telling him to "find" votes for him to change the result in Georgia. He initiated scheme to have fake Electoral College Electors cast votes for him.