“All Trump cares about is Trump,” said former Illinois Rep. Joe Walsh, one of three Republicans challenging Trump for the 2020 nomination. “He’d take down the entire planet if it helped Trump.”

And therein lies a further complicating factor for Republicans in Congress and nationally as House Democrats ramp up their impeachment proceedings into Trump’s coercion of Ukraine this summer to investigate his most feared Democratic opponent, former Vice President Joe Biden . Trump’s loyalty to his party is viewed as paper-thin, at best. While Nixon was a lifelong Republican, having served as President Dwight Eisenhower’s vice president and as a congressman and U.S. senator from California, Trump had little relationship with the GOP before he took it over by winning its presidential nomination in 2016.

“He will burn it to the ground,” predicted one former Trump White House official.

Forty-five years later, what might the GOP expect from its current president accused of trying to rig a presidential election in his favor, should Donald Trump ’s standing deteriorate to a similar level?

When the end came and Republicans told him they could not save him, President Richard Nixon agreed to walk away, in large measure for the good of his party.

Erick Erickson, a prominent conservative radio talk show host and blogger, said Republicans could try to persuade Trump into leaving by pointing out how Nixon eventually came to be seen as an elder statesman. “That might induce him,” Erickson said, adding that the other option was right out of HBO’s “Game of Thrones” series. “Otherwise, I think he’s going to re-create Daenerys Targaryen at King’s Landing.”

In fact, Republican Party officials already have tried once to get him to leave the stage. In the days following the publication in October 2016 of the “Access Hollywood” tape ― in which Trump brags that his celebrity allowed him to grab women by the genitals with impunity ― several wanted him to drop out of the presidential race and let running mate Mike Pence move to the top of the ticket. Trump not only refused but also threatened to take every Republican candidate down with him if the party tried to yank the nomination away from him.

“He’s rented the party for this entire ride,” said former Florida congressman (and former Republican) David Jolly. “I don’t think he would be compelled by an argument for the good of the party.”

Some top Republicans say that GOP senators will never request Trump’s departure as their predecessors did with Nixon because Trump commands such undying loyalty from the party’s voting base.

“Moot question,” said GOP pollster Neil Newhouse. “Senate Republicans will never ask for it. His hardcore base will not leave him.”

“This is a long way from being anywhere near that situation,” added Ron Kaufman, a longtime Republican National Committee member from Massachusetts. “There’s no analogy.”

Although many Republicans see Trump’s hold over his party as a great strength, Yale School of Medicine psychiatry professor Bandy Lee sees great danger in it to the country.

“We know that, in any situation, he will think of himself before anyone or anything else” she said. “If it became a choice, there may be no limit to what he is willing to bring down in order to salvage his fragile sense of self.”

Abusing the presidency to win re-election

In November 1972, Richard Nixon won 61% of the popular vote and scored a sweeping Electoral College victory, 520-17, losing only Massachusetts and the District of Columbia in winning a second term.

Within months, though, that victory began looking tainted as news reports, and then congressional investigations, showed that burglars paid by Nixon’s campaign had broken into the Democratic National Committee headquarters at the Watergate complex a mile west of the White House with the intent of wiretapping it.

Nixon’s approval numbers at the start of his second term, at 68% in one Gallup poll, began to decline. They had fallen below 50% by the time the Senate began formal hearings into the break-in and cover-up in May, 1973, and close to 30% by the time Nixon fired Watergate prosecutor Archibald Cox in the infamous “Saturday Night Massacre” of Oct. 20, 1973.

The number of Americans who wanted to see him removed from office, nevertheless, remained fairly low. Only 19% wanted him impeached and removed at the start of the Senate hearings. After the Saturday Night Massacre, that figure rose to and then plateaued in the mid-30s.

That phenomenon only changed after the U.S. Supreme Court ordered Nixon to release a taped conversation from June 1972, in which he is heard participating in a discussion about ordering the FBI and CIA to end the investigation into the break-in as a matter of national security. Within days, the percentage of Americans who wanted Nixon removed jumped from the low 40s to 57 on Aug. 8, 1974, the day he announced his resignation in a televised address.

In some respects, Democrats who want to impeach Trump have much more favorable circumstances than those who sought to remove Nixon.

Trump has never been popular with the majority of Americans, either as a candidate or since taking office. His current approval percentages range from the high 30s to low 40s ― where he has been pretty much his entire presidency.

Further, Trump already released a rough transcript of the July 25 phone call with Ukrainian president Volodymyr Zelensky. It documents what Trump had already admitted verbally: that he asked Zelensky to investigate Biden after having blocked $400 million in congressionally approved aid to Ukraine. “I would like you to do us a favor, though,” Trump told Zelensky.

“Really, this is all about the re-election of Donald Trump, and it’s another page out of the Nixon playbook,” Rice University presidential historian Douglas Brinkley said. “You see Trump doing the same abuse of power in getting information on Biden.”

News of Trump’s language in the call rapidly pushed dozens of House Democrats who had opposed impeachment, including Speaker Nancy Pelosi, into backing an opening of an inquiry. And that, in turn, has helped move public opinion from opposing impeachment to favoring at least the start of that process.

The web site 538 has found a measurable swing in favor of impeachment, from 51% opposing it and 40% in favor in mid-September, to 47% in favor and 45% against it today.

Brinkley said he has found the parallels between Nixon and Trump astonishing. Both abused the power of their office in efforts to win their re-elections, he said, and both then used their office and aides to try to cover it up.

The big difference is that money from Nixon’s campaign fund paid the Watergate burglars ― and he then he approved using such funds to buy their silence ― while Trump used hundreds of millions of American taxpayer dollars as leverage against the Ukrainian president, he said.

“It’s funny that everyone thought the modern Republican Party was the party of Reagan, but it’s really the party of Nixon. It’s about cronyism and the destruction of your enemies,” Brinkley said.

‘Trump can break them in half’

Yet even opposing a fundamentally less liked president who has committed an arguably worse offense might not be enough for Democrats who hope to remove Trump from office.

Nixon was contemplating resigning from the time he lost the Supreme Court decision on the “smoking gun” tape. But having his party’s elder statesman, Arizona Sen. Barry Goldwater, come to the White House with the Republican leaders of both congressional chambers to tell him that he had maybe a dozen GOP senators still supporting him likely sealed his decision to step down.

That, of course, was a different era. American politics in 2019 is not what it was in 1974.

“It’s much, much different, the political environment,” said David Axelrod, the Democratic consultant who helped lead former President Barack Obama’s 2008 campaign.

During Watergate, Goldwater and other Republicans were much more inclined to cross their president than any GOP senators are today. At that time, Tennessee Sen. Howard Baker was the ranking member of the Senate committee investigating the Watergate scandal and played a key role in the probe.

And then there are the differences between the two presidents and the media landscape, Axelrod said. “Nixon was not nearly as brazen as Trump,” Axelrod said. “Nor did he have Fox News and Breitbart.”

Sam Nunberg, a longtime former political adviser to Trump, said a more important point is that Trump’s hold over today’s Republican Party base is far more complete than Nixon’s ever was.

“If the Senate Republicans approached the president to give the president a resignation ultimatum, the uproar by the president, conservative media and his supporters would lead to the near annihilation of the Republican Party in the 2020 election that would last for multiple future cycles,” Nunberg said. “If Trump goes down, then the Republican Party goes down. This is not a symbiotic relationship. The Republicans need Trump. Trump can break them in half.”