Former President George W. Bush delivered a rare political speech Thursday in which he warned of threats to American democracy and a decay of civic engagement, a message that was interpreted as a rebuke of President Trump’s divisive leadership style.

At a New York forum sponsored by his presidential center, Bush offered a blunt assessment of a political system corrupted by “conspiracy theories and outright fabrication” in which nationalism has been “distorted into nativism.”

“We’ve seen our discourse degraded by casual cruelty,” Bush said during a 16-minute address at “The Spirit of Liberty” event. “Bullying and prejudice in our public life sets a national tone and provides permission for cruelty and bigotry. The only way to pass along civic values is to first live up to them.”

Bush did not mention Trump by name, and former aides emphasized that his message echoed words he had spoken before. But the fact that a former president was sounding the alarm about American values and the United States’ role in the world at a time when Trump has unsettled allies abroad and provoked intense political backlash at home injected his remarks with greater urgency.

The scene was remarkable in part because Bush has largely remained out of the political spotlight since leaving office amid low popularity in 2009 and had made a point not to criticize or second-guess his Democratic successor, Barack Obama. Just hours after Bush completed his speech, Obama also made a veiled critique of the Trump era, calling on Democrats at a New Jersey campaign event to “send a message to the world that we are rejecting a politics of division, we are rejecting a politics of fear.”

That Trump’s two most recent predecessors felt liberated, or perhaps compelled, to re-enter the political arena in a manner that offered an implicit criticism of him is virtually unprecedented in modern politics, historians said. Trump has been harshly critical of both Bush and Obama – calling each of them the “worst” president at one time or another – and mercilessly mocked the 43rd president’s brother Jeb Bush, the former Florida governor, during the 2016 Republican primaries.

‘THROWING DOWN THE GAUNTLET’

George W. Bush was taking aim at Trump’s “roiling of the traditional institutions of the country and, in particular, demeaning the office of the president by a kind of crude or vulgar bashing of opponents,” said Robert Dallek, a presidential historian and author.

“I think this is Bush throwing down the gauntlet and feeling that this is a man who has gone too far,” Dallek said. The discretion former presidents traditionally afford their successors “is now sort of fading to the past because of the belligerence of Trump.”

It’s not just the former presidents. Two days ago, Sen. John McCain, R-Ariz., while receiving the National Constitution Center’s Liberty Medal, lambasted “half-baked, spurious nationalism” and suggested the United States is abandoning its leadership role, an approach the Vietnam War veteran and former prisoner of war called “unpatriotic.”

McCain’s critique prompted Trump to warn him to “be careful” because he is prepared to “fight back.”

The common thread among Bush’s and McCain’s words was a defense of the post-World War II liberal order that America helped build and supported strong security alliances, a defense of human rights and an open economic system of free trade, said Richard Fontaine, who served on the National Security Council under Bush and was a foreign policy adviser to McCain.

While Republicans and Democrats have disagreed over the means to achieve such objectives, Trump has opened a direct assault on many of these ideals, Fontaine said.

“The hallmark of McCain’s and Bush’s speeches was to try to re-center us on what have been, since 1945, these traditional ends,” said Fontaine, now the president of the Center for a New American Security.

OBAMA ON CAMPAIGN TRAIL

Before leaving office, Obama had said his goal was to remain out of the political spotlight in part to afford his successor the political space to govern, as Bush had done for him. He cautioned at the time, however, that he would speak out if he saw “core values” at risk.

Since Trump took office, Obama has spoken out on occasion to defend his legacy against Trump’s attempts to repeal the Affordable Care Act, unwind U.S. participation in the Paris climate accord and impose new limits on immigration.

On Thursday, Obama returned to the campaign trail, stumping for Democratic gubernatorial candidates in New Jersey and Virginia. Though he was not as dire as Bush, Obama said in New Jersey that “some of the politics we see now we thought we put that to bed. That’s folks looking 50 years back. It’s the 21st century, not the 19th century.”

He also reminded his audience that “you can’t take this election or any election for granted.” Pausing a beat, he added: “I don’t know if you all noticed that.”

Jennifer Psaki, who worked as White House communications director under Obama, said the unifying themes between Obama and Bush are “humanity and empathy towards the American public.”

The two leaders are not weighing in on the political news of the day, she noted, but are instead “speaking to the conduct, the empathy, the leadership qualities that the American public needs of someone in the Oval Office.”

‘BIGOTRY EMBOLDENED’

Bush opened his remarks by speaking in both English and Spanish and noting that refugees from Afghanistan, China, North Korea and Venezuela were seated in the audience. This week, two federal judges temporarily enjoined Trump’s travel ban on immigrants and refugees from several countries.

Bush, who tried to advance legislation that featured a path to citizenship for undocumented immigrants, later praised the “forgotten dynamism that immigration has always brought to America.”

Bush warned that “bigotry seems emboldened” in a passage that evoked the aftermath of the white supremacist rally in Charlottesville in August, which left a female counterprotester dead. Trump had drawn intense criticism from Democrats and some Republicans for failing to clearly and promptly denounce the hate groups and suggesting equivalence between protesters on both sides.

“Bigotry or white supremacy in any form is blasphemy against the American creed,” Bush said in a line that drew the most applause. He paused and appeared to grin.

On Twitter, as liberal and moderate pundits praised Bush’s remarks, some far-right commentators mocked them by noting that many had lambasted Bush’s record of lengthy wars in Iraq and Afghanistan. Bush’s aides had at times called on the public to rally around the president in the wake of the Sept. 11, 2001, terrorist attacks and suggested criticism of Bush was unpatriotic.

Eliot Cohen, who served as a State Department counselor in the Bush administration, said those who consistently attack Bush’s record as a way to delegitimize anything he says could wind up helping Trump continue to sow division by inadvertently validating his tactics.

“Politics are now about discrediting people by ad hominem attacks, not by argumentation,” Cohen said. Those who opposed Bush’s wars have a fair point of view, he said, but their constant “demonization does help make it easier for Trump.”