Invoking a brand of Republicanism that seems a faint memory nearly eight years after he departed Washington, former President George W. Bush on Tuesday used his speech memorializing five slain Dallas police officers to deliver a not-so-subtle rebuttal to presumptive GOP nominee Donald Trump, decrying the bitter social divisions critics say Trump's campaign has all too often exacerbated.

Speaking at a memorial service at the Morton H. Meyerson Symphony Center in Dallas five days after rogue gunman Micah Johnson killed five police officers and wounded seven other officers patrolling a Black Lives Matter protest, Bush said "those of us who love Dallas and call it home have had five deaths in the family."

But the 43rd president urged the country not to give into fear or xenophobia in the wake of the attack.

"Too often we judge other groups by their worst examples while judging ourselves by our best intentions, and this has strained our bonds of understanding and common purpose," Bush said.

Though he didn't single out Trump by name, the brash billionaire loomed as the proverbial 800-pound gorilla in the room.

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In sharp contrast to Bush — who visited a mosque six days after 9/11, proclaiming Islam a "religion of peace," and who championed a pathway to citizenship for undocumented immigrants — Trump has proposed a temporary ban on Muslim immigration following ISIS-inspired terror attacks and vows to deport the estimated 11 million immigrants living in the country illegally.

Such visions of what it means to make America great again, Bush suggested Tuesday, contravene the country's fundamental principles.

"We have never been held together by blood or background," Bush said. "We are bound by things of the spirit, by shared commitments to common ideals. At our best, we practice empathy, imagining ourselves in the lives and circumstances of others. This is the bridge across our nation's deepest divisions."

It's not a new tack for Bush, who campaigned on a message of "compassionate conservatism" in 2000, urging well-heeled donors at campaign fundraisers to empathize with the plight of disadvantaged groups, from Mexican immigrants to single mothers. While that big-tent message helped Bush win 44% of the Hispanic vote in his 2004 re-election bid, Trump's appeal is strongest with a narrower, whiter slice of the electorate.

Bush has offered indirect criticism of Trump before, though he's steered clear of explicit attacks.

Stumping for brother Jeb during the former Florida governor's failed presidential bid earlier this year, Bush told voters in South Carolina, "I understand that Americans are angry and frustrated. But we do not need someone in the Oval Office who mirrors and inflames our frustration."

Like his brother and father, Bush has pointedly refused to endorse Trump — who has accused the ex-president of lying the country into the Iraq War — and will not be present at the Republican National Convention in Cleveland, where Trump is slated to formally accept the GOP nomination next week.

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