It all seemed like a replay of the 1960s race riots, which he believes tipped the 1968 presidential election to Richard Nixon, who ran as a law-and-order candidate.

Wasow says his research shows that violent, black-led protests in the 1960s reduced white support for civil rights.

Martin Luther King Jr., whose acts of nonviolent resistance drove much of the civil rights movement.

As some of the recent protests turned violent, King became a shadow commentator.

Critics of the violence quoted King's take on a notorious racist politician of his era: "Every time a riot develops, it helps George Wallace."

Congressman John Lewis, the civil rights icon, released a recent statement saying he could relate to protesters' anger and despair, but that they should be "constructive, not destructive."

President Obama also has condemned the violence that broke out at some protests.

True change comes when people "show up at the polls," she said.

But some black intellectual leaders are offering a different -- and startling -- view of what has worked for black protesters in the past.

"But the fact of history is non-violent protest has not been successful for blk Americans," Nikole Hannah-Jones, a Pulitzer Prize-winning journalist with the New York Times, said in a much-debated Twitter thread.

"The Civil Rights Movement was not non-violent," she wrote, adding she believes black protesters courted violence by whites as a strategy.

"Peaceful protest did not bring about the great civil rights legislation of the 1960s," she added.

Former NFL quarterback Colin Kaepernick's kneeling protest against police brutality spread throughout sports and beyond and helped transform the debate about racism in law enforcement.

Some argue we shouldn't apply MLK's teachings to today's black youth

Melanye Price has a message for people invoking King and nonviolence to condemn recent protesters -- stop it.

They forget that 1960s activists endured arduous nonviolent training, says Price, a professor of political science at Prairie View A&M University.

Turning the other check to violence is "not instinctual," says Price, author of "The Race Whisperer: Barack Obama and the Political Uses of Race." She says critics talk about black people as if "nonviolence was genetically implanted in us."

"People are using Martin Luther King as a weapon against them (today's protesters).

"How are angry and traumatized black folks supposed to tell the difference between sincere white allies and those whose commitment begins and ends with the charade of performative solidarity?"

Some argue violent protests will help Trump get re-elected

Some scholars believe images of black protesters choosing violence will spark a white backlash that will propel Trump to a second term.

Polls showed that nonviolent protests increased white support for civil rights, while violent protests did just the opposite, he says.

That shift was enough to hand the White house to Nixon, who had pitched his campaign to the "silent majority" of Americans who were not out in the streets.

Wasow believes images of black protesters burning buildings and looting stores reinforced a preexisting narrative in American history about black people being inherently criminal.

"That is a story about black people that the media has been telling for hundreds of years," he says.

"That script is readily available to the American public, to news reporters, and it's an easy groove for the media to slip into."

That script is so ingrained in the American psyche that even peaceful protests for racial justice provoke white anxiety, other research suggests.

Another scholar said in a recent research paper that Trump's vocal support for police during his presidential campaign in 2016 helped gain him the support of white voters who were anxious about the social changes being proposed by Black Lives Matter protesters.

While many Black Lives Matter protests were peaceful, others turned violent, especially after a white police officer shot and killed Michael Brown, an unarmed black man, in Ferguson, Missouri in 2014.

New images of black protesters looting and burning buildings could trigger anxiety among white voters who are already uneasy about the changing demographics in America, says Kevin Drakulich, the paper's lead researcher and an associate professor of criminal justice at Northeastern University in Boston.