Still, even as some leaders complained about Nixon in the press, the GOP largely gave Nixon every benefit of the doubt it could—partly because Nixon’s conservative base had stuck with him. In words that will ring true for today’s proceedings as well, historian David Greenberg outlined in his book Nixon’s Shadow how personally the president’s supporters viewed the impeachment proceedings. “During the upheaval of the late Sixties and early Seventies, millions of Americans believed that their time-honored values were being swept away by an insurgent left. Impeaching a president … was to Nixon’s supporters a metaphor,” Greenberg explained. “To them, the attack on Nixon was an attack on their mores and way of life.” It was a message reinforced each day by the White House, as Ron Ziegler and the press operation made the case that Richard Nixon was Victim No. 1.

That loyalty from the base to Nixon had caused the GOP to stand strong in the face of Watergate, even as the news worsened, the indictments piled up, and the “smell” worsened. The most loyal even created the National Citizens’ Committee for Fairness to the Presidency (NCCFP), the day’s equivalent of a super PAC, to promote the president’s defense in ads.

The Saturday Night Massacre, when Nixon ordered the firing special prosecutor Archibald Cox and precipitated the resignation of his attorney general and deputy attorney general, actually fired up and solidified his base, even though a majority of Americans disapproved. Even as the House Judiciary Committee moved to begin formal impeachment hearings in the wake of Cox’s firing and his Arizona congressional colleague Morris Udall called for Nixon’s outright resignation, Goldwater said that he thought Cox’s investigation “was getting little far afield” and that he wasn’t yet troubled by the president’s behavior himself: “I can’t see anything that’s happened that would cause either [the House or Senate] to vote for impeachment.”

In January 1974, Goldwater lashed out at the “liberal communists” and the media, saying, “[They’re] trying to egg me into saying, ‘Resign, Mr. President,’ and I’m not about to do it.” As Goldwater said, “I don’t want to go down in history that way.”

Goldwater admitted that Nixon and Watergate might be disastrous for Republicans in the 1974 election—shaving off perhaps 10 percent of the GOP vote, by his estimate—but that the party still had to stand with its leader. (The political headwinds for the party proved real: The GOP lost four of the five special congressional elections as the year unfolded.)

It wasn’t until the Nixon tapes began to seep out, both by court order and through the White House’s own attempts to publish cleaned-up transcripts, that the GOP’s support of Nixon began to seriously erode. And yet Goldwater and his fellow GOP leaders still wavered; as late as May 1974, he attended a Nixon rally in his home state where the president declared, “The time has come to get Watergate behind us and get on with the business of America.” The 14,000 fans—the Nixon base—in the arena cheered.

Yet as the summer unfolded, it became clear Nixon was a lost cause. On July 27, the House Judiciary Committee passed its first article of impeachment. Two days later, it passed a second, then the next day, a third.

And then the end—on August 5, 1974, under court pressure, the White House released the transcript of what came to be known as the “smoking gun” tape, conversations from June 23, 1972, just days after the Watergate burglary, that made clear that Nixon had tried to cover up the bungled bugging attempt. The Republican members of the House Judiciary Committee who had earlier opposed the impeachment articles announced they would support it on the House floor.

Goldwater, too, was personally angered by the way the president had betrayed his party—asking for their support even as he lied about the revelations to come. But even as he assumed the role of signing Nixon’s presidential death warrant, Goldwater was not happy about his duty; before he left for the White House, he went to the Senate floor and raised his fist to the press gallery above, exclaiming, “You are a rotten bunch!”

Goldwater, with the House and Senate minority leaders, entered the White House basement and arrived at the Oval Office around 5 p.m. on August 7. “Mr. President, this isn’t pleasant, but you want to know the situation and it isn’t good,” Goldwater said. The congressional leaders estimated that in the Senate, just 15 to 18 GOP members would vote to acquit Nixon in an impeachment trial. That level of support wasn’t even necessarily firm, they cautioned. It could get worse. The message was clear: It was time to resign—or he’d likely face removal in a Senate trial.

“Damn grim,” Nixon said.

At 5:42 p.m. Goldwater walked outside to the press cameras at the White House and reported, “Whatever decision [Nixon] makes, it will be in the best interests of our country.”

The next evening, Nixon announced his resignation in an address from the Oval Office. The long national nightmare was over.

As the impeachment trial opens for Trump in the U.S. Senate, it’s worth wondering how and when—and if—such a dramatic moment could unfold today.

Three things auger against the idea that a Goldwater exists today or that a similar moment awaits us in the weeks ahead: First, while Nixon may appear to be similar to Trump—a lonely, brooding, solitary figure—he was at the same time a creature of his party and of Capitol Hill, a man who had learned and worked the levers of power in Congress and grown up alongside the representatives who now sat in judgment on him. Nixon was so central to the GOP, in fact, that Goldwater’s 1964 run had been the only presidential campaign ticket between 1952 and 1972 that Nixon did not appear on himself. Thus, when Goldwater and the House and Senate minority leaders made that journey to the White House in early August, Nixon was talking to people he fundamentally respected. It’s hard to think of any member of the GOP in the House or Senate today that could elicit the same level of respect from Trump.

If Mitt Romney shows up at the White House and demands Trump’s resignation, does anybody—least of all Mitt—think Trump would listen or care?

Second, the Republican Party itself is deeply different than it was in 1972. It is more uniformly conservative than the GOP of the 1970s, and allegiance to Donald Trump is the sine qua non of GOP membership. Today, the moderates are gone in both parties. Trump has already chewed up and spat out of the party the #NeverTrumpers and the “elder statesmen”—types like former Tennessee Sen. Bob Corker. Not even electorally vulnerable senators like Susan Collins have had meaningful breaks with Trump on key votes. Even more importantly, the GOP was fully a minority party in 1974, controlling neither the House nor the Senate, whereas Mitch McConnell as Senate majority leader has a much stronger hand to play in the trial as it unfolds. McConnell can tamp down and de-emphasize the impeachment trial as much as he wants.

Third and perhaps most definitively, resignation was already in the air by the time Goldwater threw in the towel himself. In 1974, party leaders like Republican Sen. Howard Baker felt they had a duty to take the impeachment inquiry seriously—and, as time passed, expressed their own doubts—in sometimes halting terms—about whether Nixon was truly innocent. Since the end of 1973, aides and members of Congress—even Nixon’s own lawyers—had repeatedly told Nixon that they believed his position, presidency and moral authority were growing increasing untenable. The seeds had already been planted.

For all of the whispers of the 25th Amendment, from Rod Rosenstein or others, for all of the high-profile insult-laced tirades and verbal sparring matches Trump has gotten into with aides, staff and Cabinet secretaries, there have been no reports that resignation has ever been an option formally suggested to Trump.

As Trump’s circle has tightened and he’s expelled heavyweights like John Kelly, Jim Mattis, H.R. McMaster and Rex Tillerson, replaced them with ultraloyalists like Mike Pompeo and Bill Barr and downgraded and sidelined voices like Mick Mulvaney, it’s not clear that any outside adviser could or would offer any hard, straight talk to the president about the ongoing damage he could cause the country. And it seems clear that Trump’s family remains fully in his corner, too. Similarly, his announcement Friday that his impeachment legal team would include Ken Starr, Robert Ray, Pam Bondi and Alan Dershowitz seems to make clear that the president is surrounding himself with public pugilists rather than sober legal minds with the nation’s best interests in mind.

Moreover, and perhaps most troubling, while at the end of the day, Nixon cared about the office of the presidency as a historical institution and moral force in America, there is no sense today that Trump separates his own interests from the office he holds.

As Goldwater hinted to the cameras after their Oval Office meeting, Nixon understood that the presidency was an office one held for only a period of time, a role that had begun long before he arrived at the White House and one that he hoped would continue long past his two terms.

Unfortunately, it’s not clear that Trump cares what shape the presidency is in when he leaves office, whenever that will be.