WASHINGTON — The nation’s cities were in flames amid protests against racial injustice and the fiery presidential candidate vowed to use force. He would authorize the police to “knock somebody in the head” and “call out 30,000 troops and equip them with two-foot-long bayonets and station them every few feet apart.”

The moment was 1968 and the “law and order” candidate was George C. Wallace, the former governor of Alabama running on a third-party ticket. Fifty-two years later, in another moment of social unrest, the “law and order” candidate is already in the Oval Office and the politics of division and race ring through the generations as President Trump tries to do what Wallace could not.

Comparisons between the two men stretch back to 2015 when Mr. Trump ran for the White House denouncing Mexicans illegally crossing the border as rapists and pledging to bar all Muslims from entering the country. But the parallels have become even more pronounced in recent weeks after the killing of George Floyd as Mr. Trump has responded to demonstrations by sending federal forces into the streets to take down “anarchists and agitators.” The Wallace-style tactics were on display again on Wednesday as Mr. Trump stirred racist fears about low-income housing moving into the suburbs.

“In the presidential campaign of 1968, my father, Governor George Wallace, understood the potential political power of downtrodden and disillusioned working class white voters who felt alienated from government,” his daughter, Peggy Wallace Kennedy, said by email the other day. “And Donald Trump is mining the same mother lode.”

Former President Barack Obama implicitly made the comparison between the two men during a eulogy on Thursday for John Lewis, the civil rights icon and longtime congressman. “George Wallace may be gone,” Mr. Obama said, “but we can witness our federal government sending agents to use tear gas and batons against peaceful demonstrators.”

It may seem incongruous to see Mr. Trump, a New Yorker born to wealth with no ties to the South beyond Trump-branded property in Florida, embracing the same themes as Wallace, who was proud to call himself a “redneck” segregationist from hardscrabble Alabama. Yet it speaks to the enduring power of us-against-them politics in America and the boiling pot of resentment that Mr. Trump, hoping to save his presidency, is trying to tap into a half-century after Wallace did, hoping to win the presidency.

To go back and read or listen to Wallace’s speeches and interviews from that seminal 1968 campaign is to be struck by language and appeals that sound familiar again, even if the context and the limits of discourse have changed.

Like Mr. Trump, Wallace denounced “anarchists” in the streets, condemned liberals for trying to squelch the free speech of those they disagreed with and ran against the elites of Washington and the mainstream media. He vowed to “halt the giveaway of your American dollars and products” to other countries.

“One of the issues confronting the people is the breakdown of law and order,” Wallace said at his campaign kickoff in Washington in February 1968. “The average man on the street in this country knows that it comes about because of activists, militants, revolutionaries, anarchists and communists.”

Just last week, Mr. Trump framed the current campaign in similar terms. “So it’s a choice between the law and order and patriotism and prosperity, safety offered by our movement, and the anarchy and chaos and crime and socialism,” he told a tele-rally in North Carolina. In tweets this week, he promised “all of the people living their Suburban Lifestyle Dream that you will no longer be bothered or financially hurt by having low income housing built in your neighborhood.”

Like the pugnacious Mr. Trump, Wallace enjoyed a fight. Indeed, he relished taking on protesters who showed up at his events. “You know what you are?” he called out to one. “You’re a little punk, that’s all you are. You haven’t got any guts.” To another, he said, “I may not teach you any politics if you listen, but I’ll teach you some good manners.”

Recalling the time protesters blocked President Lyndon B. Johnson’s motorcade, Wallace insisted that he would never let that happen to him. “If you elect me the president and I go to California or I come to Arkansas and some of them lie down in front of my automobile,” he said, “it’ll be the last thing they’ll ever want to lie down in front of.”

Mr. Trump has made similar chest-beating threats. “When the looting starts, the shooting starts,” he wrote on Twitter after protests turned violent in Minneapolis following Mr. Floyd’s death under the knee of a white police officer. A few days later, the president said that protesters who tried to enter White House grounds would be greeted “with the most vicious dogs, and most ominous weapons” and that Secret Service agents would “quickly come down on them, hard.”

Among those who saw an analogy between the two men from the start was Mr. Lewis, who was beaten on the Selma bridge in Wallace’s Alabama in 1965 and died this month. “It is a reasonable comparison,” Mr. Lewis said in an interview with The New York Times and CNBC in 2016. “See, I don’t think Wallace believed in all of the stuff he was preaching. I think Wallace said a lot of stuff just to get ahead. I don’t think Trump really believes in all this stuff, but he thinks this will be his ticket to the White House.”

More recently, former Vice President Joseph R. Biden Jr. has said that Mr. Trump is “more George Wallace than George Washington.” Mr. Trump’s campaign fired back this week in a statement by Katrina Pierson, a senior campaign adviser to the president, who credited him with increasing funding for historically black schools and signing criminal justice reform.

“There’s only one candidate in this race who bragged about receiving an award from George Wallace, and that’s Joe Biden,” Ms. Pierson said. “Biden also said that Democrats needed a ‘liberal George Wallace, someone who’s not afraid to stand up and offend people.’”

Both quotes refer to articles in The Philadelphia Inquirer, one in 1975 about Mr. Biden’s opposition to busing and another in 1987 mentioning a campaign stop in Alabama during his first presidential campaign. The Biden campaign countered with other clips from the 1970s in which Mr. Biden criticized Wallace and vowed to vote Republican if he won the Democratic presidential nomination in 1976.

Wallace made his name as the most prominent segregationist of his time but he neither started nor ended that way. Unlike Mr. Trump, he was a small-town boy from Clio, Ala., who grew up to jump into politics as a progressive, eager to help the disadvantaged with New Deal-style programs. As a judge and a Democratic candidate for governor in 1958, he made a point of promising equality for Black Alabamians. But when he lost that contest to a candidate who demagogued on segregation, Wallace told an aide that “I was out-niggered and I will never be out-niggered again.”

After winning the governor’s mansion with a hard-core racist appeal, he came to national attention in 1963 by promising in his inaugural address “segregation now, segregation tomorrow, segregation forever” and months later by standing in the schoolhouse door in a failed effort to block the integration of the University of Alabama. Wallace that same year ordered the Confederate flag flown above the State Capitol, where it remained for 30 years before being taken down for good.

In “Settin’ the Woods on Fire,” an acclaimed 2000 documentary on his life, Wallace was quoted telling an associate who asked about his race-baiting that he wanted to talk about issues like roads and education but that he never got as much attention as when he thundered about race.

Wallace made his first faint stab at the White House in 1964, but when he ran for real in 1968 he bolted from the Democratic Party to lead the ticket of the American Independent Party. Trying to appeal to a national audience, he toned down the explicitly racist language and used code words instead, defending states’ rights, slamming court-ordered busing and promising law and order.

Like Mr. Trump, he denied trafficking in racism and turned the accusation around on his opponents. “I think the biggest racists in the world are those who call other folks racist,” Wallace said. “I think the biggest bigots in the world are those who call other folks bigots.”

In an interview on “Face the Nation” on CBS in Washington, he said his white critics called him a racist while fleeing to the suburbs so they did not have to send their children to schools with Black children. “This is a segregated city here because of the hypocrites who moved out,” he said. “This is the hypocrite capital of the world.”

Mr. Trump, who has come to the defense of the Confederate flag by mocking NASCAR for banning it, likewise tries to turn the racism charge against his critics. Last year, he asserted that four congresswomen of color were “a very Racist group of troublemakers,” referred to a Black congressman who angered him as “racist Elijah Cummings” and declared that the Rev. Al Sharpton “Hates Whites & Cops!”

After Mr. Biden last week called him “the first” racist president, Mr. Trump repeated his assertion that he had “done more for Black Americans than anybody with the possible exception of Abraham Lincoln.” (These are both ahistoric statements, of course. Many presidents were racist and early on even slave owners, while Lincoln was hardly the only president to have done more for Black Americans than Mr. Trump.)

In that 1968 race, Richard M. Nixon beat Hubert H. Humphrey, but Wallace won five states in the Deep South — Alabama, Arkansas, Georgia, Louisiana and Mississippi — the last time an independent or third-party candidate captured any states in the Electoral College.

Wallace ran again in 1972, this time as a Democrat, but was felled by a would-be assassin’s bullets that left him paralyzed. He ran again in 1976 from a wheelchair, winning Democratic contests in three states but losing the nomination to a more moderate Southerner, Jimmy Carter.

By late in life, Wallace had a change of heart and repented his earlier racism, going so far as to call Mr. Lewis and others to personally apologize. He ran for governor one last time in 1982 by reaching out to Black voters and after winning installed many Black appointees in state government. At the 30th anniversary of Selma, he sang “We Shall Overcome” with Black Alabamians. When Wallace died in 1998, Mr. Lewis wrote an Op-Ed article in The Times forgiving him.

Mr. Trump, for his part, shows no signs of backing down and was the only living president to neither attend Mr. Lewis’s memorial service on Thursday nor send a message to be read. Wallace’s daughter said Mr. Trump understood, as her father did, that “the two greatest motivators for disaffected voters” are “hate and fear.”

“Mr. Trump exudes the same willingness to fight rather than to seek rational solutions much like my father did in 1968,” Ms. Wallace Kennedy said. “Both promise to be a president with personality and bravado who is ready to fight first and worry about the consequences later.”