President Trump speaks in the Rose Garden on July 29. (Jabin Botsford/The Washington Post)
Kyla Sommers is the editor of the History News Network at the George Washington University and a historian of Washington, D.C.

On Saturday, President Trump attacked Rep. Elijah E. Cummings and the city of Baltimore in a series of tweets. Trump characterized Cummings’s district, which includes more than half of Baltimore County, as a “disgusting, rat and rodent infected mess” that is “very poor, very dangerous, and very badly run.”

The derogatory tweets sparked outrage, and since then Trump has been doubling down. He said in one tweet Monday that Baltimore had the “worst Crime Statistics in the Nation” and in another referred to “King Elijah’s Baltimore Fail.” Why? As reported by The Washington Post, his advisers believe these racialized attacks boost the president “among his political base — resonating strongly with the white working-class voters he needs to win reelection.”

Trump is only the most recent in a long line of conservative leaders who have adopted the strategy of stoking fears of urban crime and decline to rally white voters, undermine liberal efforts at civil rights reform and advance policies that have dangerous consequences for communities of color.

While Trump attacked Baltimore, its neighbor to the south, Washington, has long captured the attention of policymakers who want to use the purported plight of urban areas to further their agenda. The symbolic significance of the capital and federal control over its governance made Washington unique among cities in the early 1950s. Most schools, especially those in the South, were slow to comply with the 1954 Brown v. Board of Education Supreme Court decision. Not so in Washington, which took immediate action thanks to the prodding of President Dwight D. Eisenhower. D.C. schools were soon thrust into the national spotlight by those trying to safeguard segregation.

Southern segregationists in Congress, fighting a desperate rear-guard action to stave off integration in schools back home, tried to use Washington’s experience to make the case that school integration had been bad for the city and would be equally bad elsewhere. While Eisenhower argued that Washington was a positive “model for the rest of the country,” Rep. James Davis (D-Ga.) charged that the District was actually a cautionary tale with “tragic results which come from the breakdown of segregation and substitution of an integrated public-school system.”

In 1957, during a House subcommittee hearing on integration in D.C. schools, William Gerber, the subcommittee’s chief counsel, asked school administrators and teachers leading questions to suggest that integration had destroyed Washington’s schools. He pushed the narrative that black students were inherently intellectually inferior, caused dangerous disciplinary problems and would corrupt white children (among other things). Although many teachers defended desegregation and assistant superintendent Carl Hansen called it a “miracle of social adjustment,” the committee sent distorted reports to schools in the South so that they could use this purported information as an excuse to delay integration.

The Southern distortion and weaponization of events in Washington went beyond integrated schools. That same year, famous author Willie Snow Etheridge was mugged in the District right off Connecticut Avenue — a “good” and white part of town. Again, Southern members of Congress distorted the story to add ammunition in their fight against integration. Congressmen bemoaned the “terror”: The capital would be “an after dark ghost city” unless Congress passed stronger anti-crime laws, one asserted. Another blasted the District as “a half-civilized place where it is unsafe to venture into the streets at night,” while a third charged that crime made the city a “national disgrace.”

This sensationalized concern over crime, however, was just as disconnected from reality as the narrative about D.C. school integration. At the time of the Etheridge incident, the D.C. crime rate was one of the lowest in the country, and 10 percent lower than the previous year. Yet the narrative of a crime-plagued city stubbornly persisted: In 1956, after D.C. crime decreased by nearly 20 percent over three years, citizens associations continued to ask Congress for more police, because residents “are afraid to go out after dark to meetings or for social occasions.”

Why the contradiction? Worry about crime was a cover for racialized fears. As the District became a majority-black city in 1957, it was no coincidence that white Washingtonians reported feeling less safe and believed that the District was one of the most dangerous cities.

Southern lawmakers helped to stoke these fears. Sen. Olin Johnston (D-S.C.) made speeches in Congress almost daily condemning D.C. crime and the “chronic ailments that accompany forced integration.” To Sen. Allen Ellender (D-La.), crime in the District proved “his contention that Negroes cannot govern themselves.” Davis chimed in that the District was “noted for the great number of serious crimes committed in its limits” and bluntly stated, “Negroes are responsible for this high crime rate.”

So prevalent did this narrative become that in 1964, Republican presidential nominee Barry Goldwater turned the story of D.C. crime into a national campaign issue about not just race but also the failures of liberal leadership. “Our nation’s capital now ranks third out of 16 comparable cities in robberies,” he said, "… a place of shame and dishonor that reflects directly on lack of leadership and concern in the White House.”

Four years later, Richard M. Nixon sounded similar notes, using D.C. crime as part of his “Southern strategy” that used racially coded language to gain white Southern support. He blamed President Lyndon B. Johnson for an upsurge in D.C. crime and for the civil disturbances in the capital after the assassination of the Rev. Martin Luther King Jr.

Then he took this critique a step further. Assailing Washington as the “crime capital of the world,” Nixon used it as the prime example of why “get tough” policies were needed: “D.C. should not stand for Disorder and Crime,” he argued. “A Nixon administration will sweep the streets of Washington clean of these marauders and criminals and remove from this city the atmosphere of aggression that hangs over it.”

What had once been the language of Southern segregationists had now become mainstream in the Republican Party. It helped the GOP win elections by appealing to white voters’ prejudice, and then paved the way for policies that sparked a punitive impulse with real consequences for the black community: mass incarceration and the curtailment of civil liberties.

After Nixon entered office, he defunded much of Johnson’s War on Poverty and replaced it with a “War on Crime” in the District that eventually became law with the passage of the 1970 D.C. crime bill. As historian Elizabeth Hinton has documented, the bill “pioneered” techniques such as preventive detention (permitting the detention of a suspect without bail for up to two months), enacted mandatory minimums and included other tough-on-crime provisions that would spread nationwide. Today, we understand that decades of such policies have devastated urban neighborhoods and families while discrediting solutions to urban problems that liberal reformers had tried to enact, leaving those problems festering a half-century later.

Today, Trump and his political advisers are reinvigorating this historical strategy that uses race to attract white supporters and detract legitimacy from progressive policies. Trump, like Nixon before him, knows that criticizing a majority-black city stokes racist sentiment among his base without the sort of explicit condemnation of African Americans that he knows is politically unpalatable. Although he and his allies will insist that discussing crime rates or rats is not racist, history tells us that a crucial pool of voters knows exactly what Trump means.