'Bigotry seems emboldened': George W Bush rebukes Trump

George W Bush issued a sharp denunciation of bigotry, white supremacy and falsehoods on Thursday, in what was seen as a clear rebuke of politics in the age of President Donald Trump.

"We've seen nationalism distorted into nativism and forgotten the dynamism that immigration has always brought to America," the 71-year-old ex-president said, after months of Trump's efforts to rein in immigration and slow or outright ban the flow of primarily Muslim refugees into the United States.

"We've seen our discourse degraded by casual cruelty. At times it can seem like the forces pulling us apart are stronger than the forces binding us together."

The two-term former president warned in a speech in New York that the coarsening of the national tone and divisive themes are threats to American democracy.

"Bigotry seems emboldened. Our politics seem more vulnerable to conspiracy theories and outright fabrication," Bush said.

Though he did not mention Trump by name, Bush offered an implicit rebuke of the current administration and the controversial politics that emboldened millions of voters who swept Trump to victory last November.

"Bigotry or white supremacy in any form is blasphemy against the American creed," Bush said, two months after Trump said "both sides" were to blame when a neo-Nazi rally in Virginia turned violent.

He spoke the same day as white supremacist figure Richard Spencer tried to give a speech at a Florida university, but was shouted down.

Argument "turns too easily into animosity," Bush added. "Disagreement escalates into dehumanisation".

Bush had declined to endorse Trump's candidacy.

Thursday's speech - at the Bush Institute's Spirit of Liberty event - marked a departure from that silence, an expression of concern by a former leader in a unique moment in the nation's history.

The 43rd president, observing America's "fading confidence" in free markets and international trade, lamented the "return of isolationist sentiments" in the country.

Trump had made opposition to Bush’s “nation-building” foreign policy, a major theme in his campaign.

Bush's comments reverberated through political Washington.

"Important speech by my friend," said Senator John McCain, who challenged Bush for the 2000 Republican presidential nomination.

Bush's remarks came three days after McCain delivered his own speech appearing to criticise Trump's ideas and politics.

McCain slammed what he called "half-baked, spurious nationalism" in his speech, a remark widely taken as a rebuke of Trumpism.

Democratic Congressman Ted Lieu thanked Bush in a Twitter post for “speaking truth” about Trump.

However, Bush’s critics pointed to his own problematic policies when he was in office, namely invading Iraq under false pretences - a war that was a catalyst to years of turmoil in the Middle East, including the rise of the Islamic State group.

"Dems praising George W Bush shows they have no problem with oligarchy & war crimes - they just want the ruling class to use nicer rhetoric," the US Green Party said on Twitter.