During the second presidential debate, when a well-dressed black man asked Donald Trump if he "could be president of all the people," Trump immediately launched into his now-familiar riff about the inner cities and how terrible they are. "You go into the inner cities, it's 45 percent poverty," he said. "The education is a disaster. Jobs are essentially nonexistent … It can't get worse." Trump apparently assumed this man had come from one of the worst neighborhoods in St. Louis.

It’s a type of assumption that many American blacks are familiar with, but today, while it may be true that everyone who lives in a certain ghetto is black, it is patently untrue that everyone who is black lives in a ghetto.

Although racial differences in economic status remain a negative feature of American society, many blacks now work in a wider range of occupations than ever. Though blacks remain overrepresented in menial jobs and many inner-city black communities have been decimated by deindustrialization, racial discrimination, and the resulting "structural poverty," the black middle class is now the largest in history.

Many black people are now thriving in professional positions where they rarely appeared before — as doctors, lawyers, professors, corporate executives, respected entertainers, professional athletes, and major elected officials. Many of these people also live in racially mixed neighborhoods from which they were once excluded; they attend some of the best schools and universities in the country, places that only recently excluded them.

But this class of black people is generally obscured in the minds of many whites, by of the omnipresence and salience of what I have called the "iconic ghetto." In sociology, a "master status" refers to a facet of identity that serves as the primary identifying characteristic of a person. The iconic ghetto acts as a "master status" in American life, superseding whatever else a black person might claim to be. This stereotypical image of the ghetto works to define the black body as a powerful symbol in American culture — the iconic Negro.

The perils of crossing from one space into another

Educated and well-off black people are generally considered the exception, and not the rule. Thus, typically, when black people venture into the larger society — into the areas blacks generally perceive as "white space," including corporations, universities, suburbs, and the auditoriums where presidential debates are held — the ghetto icon both follows and precedes their presence, hovering overhead and negatively affecting their relations with their fellow citizens.

This dynamic influences, if it does not outright determine, how their fellow citizens perceive and regard them — at least initially. If black people can negotiate, or "dance," their way out of this, their status as acceptable occupants of white space is usually then only provisional. As black people, they can always have something more to prove, and almost any white person can demand such proof.

Recently, as the Washington Post reported, a black female doctor was traveling on an airplane when another passenger required medical assistance. The flight attendant, a white female, incredulous at the black doctor's identity claims, initially declined her offer to help ("Oh, no, sweetie, put [your] hand down"). But when a white male passenger appeared and presented himself as a doctor, the flight attendant readily accepted his assistance.

Because of the legacy of American racism, but also the iconography of cities and the widely shared belief that blacks occupy only the very bottom rungs of society, many Americans are susceptible to this stereotype. This dynamic most often manifests itself in what Hillary Clinton, drawing on academic work, has called "implicit bias," a subconscious and powerfully negative view of all black people that immediately burdens anonymous blacks with a deficit of credibility — regardless of their accomplishments or character. Thus, the ghetto icon works as a kind of yoke that all black people must navigate, or carry, as they seek regard from strangers they encounter.

As a result of historic racial segregation, including the dynamic of white flight, the wider society is replete with essentially white neighborhoods, schools, workplaces, churches, towns, and cemeteries, contributing to the dominant white sensibility.

White space, black space, and the "cosmopolitan canopy"

White Americans typically see these spaces as normal, everyday reflections of "civil society," and may even regard them as "diverse." But what others see as "diverse," black people may perceive as homogeneously white and relatively privileged.

While the respective white and black spaces may appear to be racially homogeneous, typically they can be sub-classified in terms of ethnicity and social class. "White spaces," for instance, often include not only traditional Americans of European descent but also recently arrived European immigrants and visitors as well as others who may be perceived as phenotypically "white." Comparatively lighter-complexioned blacks, and members of some other ethnic groups, such as Asians, may be granted a pass.

Meanwhile, the people inhabiting "black space" are not always simply traditional African Americans, but may be sub-classified as African, Latino, Haitian, Caribbean, Cape Verdean, and so on. Accordingly, the racially mixed urban space, a version of which I have referred to elsewhere as "the cosmopolitan canopy," exists as a diverse island of civility located in a virtual sea of racial segregation.

The city today can be conceptualized as white space, black space, and racially mixed space, and these spaces are typically in flux. But while white people usually avoid black space, black people are required to navigate the white space as a condition of their existence.

By definition, white people predominate in white spaces, and by implication blacks and other people of color are often absent there or when present made to feel uneasy. In the white space, the most acceptable black person is one who is either "in his place," working as a janitor or as a service person, or one who is otherwise being vouched for by white people in good standing. Such a black person is less likely to be disturbing to the perceived racial order of the typical white setting. When the black person does not appear in a subordinate role, however, dissonance may occur.

In white space, "Can I help you?" can be an aggressive challenge

In many such spaces, black persons can expect to be racially profiled or to encounter acute disrespect on the basis of blackness. Blacks may be highly self-conscious in such settings, and may sense that they are in hostile territory even when this is not the case. The closer the ghetto, the more self-conscious the black person may feel, its proximity complicating his presence; on the outskirts of a ghetto, white people become more defensive and scrutinize the anonymous black person more thoroughly, wondering whether he or she may mean them harm.

Given the civil rights struggles of the 1950s and 1960s, as well as the racial incorporation process that has produced the largest black middle class in history, blacks are now generally allowed to venture into places that are absolutely lily-white, and to expect to be present there uneventfully, often as the only black person present. But they may be mistaken for someone of menial position. Polite company may not overtly declare this as white space, which would draw unwanted attention to the observation, but some of the most marginal whites might do so, effectively drawing the color line and putting the black person in his or her "place."

Educated and well off black people are generally considered the exception, and not the rule. Thus when black people venture into the larger society — into corporations, universities, suburbs, and the auditoriums where presidential debates are held — the ghetto icon both follows and precedes their presence.

Black people sometimes refer to such incidents as the "nigger moment," a moment of acute disrespect based on their blackness. Such moments vary in intensity, ranging from incidents they consider to be minor to those they know to be major. Black people generally try to ignore minor incidents — yet they understand that major incidents can change their lives or even get them killed. When such a moment occurs, the black person may be so affected that his or her orientation towards the white space can be altered, at times profoundly.

Several years ago, I vacationed in Wellfleet, Massachusetts, a pleasant Cape Cod town full of upper-middle-class white vacationers, tourists, and working-class white residents. During the two weeks that my family and I spent there, I encountered very few other black people. We had rented a beautiful cottage about a mile from the town center, which consisted of a library and a few restaurants and stores catering to tourists. Early one weekday morning, I jogged down the road from our cottage through the town center and made my way to Route 6, which runs the length of the Cape from the Sagamore Bridge to Provincetown. It was a beautiful morning, about 75 degrees, with low humidity and clear blue skies. I had jogged here many times before.

At 6 am, the road was deserted, with only an occasional passing car. I was enjoying my run that morning, listening to the nature sounds and feeling a sense of serenity. It seemed I had this world all to myself. Suddenly a red pickup truck appeared and stopped dead in the middle of the road. I looked over at the driver, a middle-aged white man, who was obviously trying to communicate something to me. He was waving his hands and gesticulating, and I immediately thought he might be in distress or in need of help, but I could not make out what he was saying.

I stopped, cupped my hand to my ear to hear him better, and yelled back, "What did you say?" It was then that he made himself very clear. "Go home! Go home!" he yelled, dragging out the words to make sure I understood. I felt provoked, but I waved him off and continued on my way. Black people in white spaces commonly experience such incidents, and generally try to disregard them, but are affected by them nonetheless.

In some public white spaces, such as upscale shops or restaurants, a black person is often approached with a disingenuous question such as "Can I help you?" Most blacks, particularly young males, have experienced this question time and again; of course, it is not an actual offer of assistance but a challenge to the black person’s right to be on the premises. A more direct question might be: What are you doing here? But most defenders of such spaces prefer to be indirect in their challenges, which avoid direct insult based on skin color (and also possibly a lawsuit). Nonetheless, the perceptive black person on the receiving end of such encounters understands that he has been assigned a provisional status: One false move and the police or security will be summoned.

If black people wish to succeed, they must enter white space

Given these difficulties, many blacks approach the white space ambivalently, and usually for instrumental reasons. When possible, they may avoid it altogether or leave it as soon as possible. In exiting the white space, however, a black person can feel both relief and regret — relief for departing a stressful environment and regret for perhaps leaving prematurely. For the white space is where many social rewards originate, whether the brief pleasures of an elegant night on the town or life-course affecting sources of cultural capital: education, employment, privilege, prestige, money, and the promise of general acceptance among the successful.

To obtain these rewards, blacks must venture into the white space and explore its possibilities. To prevail, they must manage themselves within this space. But all too frequently, prejudiced actors pervade the white space and are singly or collectively interested in marginalizing the black person, actively reminding him of his outsider status.

The existence of racial segregation is a pervasive feature of American life, rooted in the assumption that whites and blacks "belong" in different physical spaces — with some of those spaces offering more opportunities and amenities than others. Donald Trump’s blithe assumption that all black people live in ghettos with sky-high unemployment and desperate schools takes what is usually an unspoken fact of American life and makes it brutally explicit.

Elijah Anderson is the William K. Lanman Jr. Professor of Sociology at Yale University. He is the author of, among other books, The Cosmopolitan Canopy: Race and Civility in Everyday Life.