FORT LAUDERDALE, Fla. — Jeb Bush and his aides had envisioned a big, inclusive, high-minded speech about race on Friday in his home state of Florida, a chance to bring his message of colorblind opportunity to a prestigious group of African-American leaders.
In a rare gesture of bipartisanship, Mr. Bush even planned to warmly quote President Obama, usually the object of his derision.
Then Hillary Rodham Clinton stomped all over those plans.
In a biting surprise attack, delivered as Mr. Bush, the former Florida governor, waited backstage here at the annual convention of the National Urban League, Mrs. Clinton portrayed him as a hypocrite who had set back the cause of black Americans.
It was an unexpected moment of political theater that seemed to presage what could be a bitter general-election rivalry between two of the biggest names in American politics.
Mrs. Clinton, a Democratic candidate for president, latched onto Mr. Bush’s campaign slogan and the name of his “super PAC” —Right to Rise, his shorthand for a conservative agenda of self-reliance and hope — and turned it into a verbal spear.
“People can’t rise if they can’t afford health care,” Mrs. Clinton said to applause from conventiongoers, a dig at Mr. Bush’s opposition to the Affordable Care Act.
“They can’t rise if the minimum wage is too low to live on,” she said, a jab at his opposition to raising the federal minimum wage.
“They can’t rise if their governor makes it harder for them to get a college education,” she said, a critique of Mr. Bush’s decision as governor to eliminate affirmative action in college admissions.
When Mr. Bush reached the lectern, declaring, “I believe in the right to rise in this country,” the scent of political gunpowder was still in the air.
The assault on her Republican rival was all the more striking because the Bush and Clinton families make a point of highlighting their friendly ties: Former Presidents Bill Clinton and George W. Bush appear on this week’s cover of Time magazine.
Mr. Bush appeared unprepared to respond, thanking Mrs. Clinton for joining him at the event but otherwise leaving her criticism unanswered in his own speech.
Mr. Bush’s aides, however, could barely hide their disgust over Mrs. Clinton’s remarks, which they spoke of, bitterly, as uncivil and uncalled-for.
On Twitter, Tim Miller, Mr. Bush’s communications director, called it a “Clintonesque move to pass over chance to unite in favor of a false cheap shot.”
Allie Brandenburger, a spokeswoman for Mr. Bush, followed up with an email saying, “The Urban League deserved better.”
Despite the broadsides from Mrs. Clinton, Mr. Bush’s speech was well received. He won applause when he recalled his decision to remove the Confederate battle flag from the grounds of the Florida Capitol in 2001. And he spoke emotionally of the massacre of nine black parishioners in Charleston, S.C., in June and of the forgiveness their survivors had expressed for the man charged in the shooting.
“In the community of that city, we found such grace, such purity of heart, such heroic goodness, such boundless mercy, all gathered up in one story,” Mr. Bush said.
He quoted both the Rev. Dr. Martin Luther King Jr. and Mr. Obama. “When President Obama says that ‘for too long, we’ve been blind to the way past injustices continue to shape the present,’ he is speaking the truth,” Mr. Bush said to applause.
But he did not directly address the rash of police shootings of unarmed black men that dominated discussions at the Urban League conference this week. Instead, he called more obliquely for rebuilding trust in “America’s vital institutions.”
“That happens,” he said, “one person at a time. One politician at a time. One police officer at a time.”
In her remarks, Mrs. Clinton took a more direct approach, ticking off the names of African-Americans who have died after interactions with law enforcement — including Eric Garner, Walter L. Scott andFreddie Gray — to knowing nods in the audience.
“These names are emblazoned on our hearts,” she said. “We’ve seen their faces; we’ve heard their grieving families.”
She spoke explicitly about racial discrimination, saying it still played a major role in determining “who gets ahead in America and who gets left behind.”
She added: “We can’t go on like this. We are better than this. Things must change.”
Toward the end of her speech, Mrs. Clinton turned to those who, in her telling, do not live up to their own words on the subject of racial injustice, singling out Mr. Bush, not by name but by implication, over and over.
Those attending the Urban League conference, who lean Democratic, took notice.
Cherie LaCour-Duckworth, a Clinton supporter, said she had paid little attention to what Mr. Bush said. Mrs. Clinton, she said, “set the stage for him.”
Norma Richards, who traveled to the conference from Ohio, said she was struck by Mr. Bush’s decision to talk about race so indirectly. “He wasn’t really strong about social injustice,” she said.
But her real objection to Mr. Bush, she said, stemmed from the presidential contest between George W. Bush and Al Gore in 2000, in which Florida played a decisive role. “They stole the election,” she said. “I can’t get that out of my head.”
The conference Friday had offered a chance for Senator Bernie Sanders, the Vermont independent who is challenging Mrs. Clinton for the Democratic nomination and has generated a loyal following among white liberals, to appeal more directly to black voters. But his speech highlighted just how much work he still has to do.
At one point, Mr. Sanders begged for the crowd’s indulgence to discuss his campaign platform before focusing on the “save our cities” subject of the gathering. But he called that “your theme” — an off-key remark, and one that echoed a speech he made on Thursday, in which he twice referred to Latinos as “your people” before the United States Hispanic Chamber of Commerce.
Ben Carson, a Republican who was the sole black candidate to speak here, took a tough-love approach that seemed to inspire little enthusiasm from the crowd. Mr. Carson, a retired neurosurgeon, never mentioned the high-profile deaths of unarmed black men and women in police custody and held himself up as a model of how ambition and education could rescue poor African-Americans from poverty.
He called on black parents to talk to their sons “about how they conduct themselves.”
“If you conduct yourselves in certain ways,” he said, “you are going to run into trouble, not only with law enforcement but with the guy down the block.”
Herman Wallace, an attendee from Kansas City, Mo., was unmoved. “Carson,” he said, “talked about himself.”