(CNN) President Barack Obama was delivering a speech before a joint session of Congress when a white lawmaker jabbed his right index finger at Obama and called him a liar.

The heckling came during his September 2009 address on health care. Obama was telling lawmakers that his plan wouldn't cover undocumented immigrants when Republican Rep. Joe Wilson of South Carolina yelled, "You lie!"

Linnyette Richardson-Hall, an African-American event planner, watched Wilson's outburst on live television in disbelief.

"My alter-ego, the hood-chick, came out of me," says Richardson-Hall. "I said, 'I know you just didn't do that.' To see him get disrespected so badly, it gut-punches you."

Richardson-Hall has restrained herself more than she ever expected in the past eight years. She fumed when she saw a poster of Obama dressed as an African witch doctor, online images of First Lady Michelle Obama depicted as a monkey, and racist Facebook comments by white people she thought she knew. Now, as Obama approaches his final months in office, she and others have come to a grim conclusion:

I didn't know how racist America was until it elected its first black president.

"What has happened over the past eight years -- there's no way to unlive or unsee it," says Mashaun D. Simon, a political blogger and teaching assistant at Emory University's Candler School of Theology in Atlanta.

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There's been a lot of talk about angry white Americans and the rise of Donald Trump, the presumptive Republican presidential nominee. But what about the anger that many blacks and others have felt over the treatment of Obama? What might that anger give rise to, and how is it changing them?

A psychological shift is taking place among many blacks, and it can be heard in countless conversations over dinner tables, in barbershops and on social media. Some say they've never felt so much pessimism about white America, such hopelessness.

They're almost relieved to see Obama go.

It's not that black people aren't proud of Obama or his family. His approval rating among blacks has been astronomically high throughout his presidency. But that pride has been accompanied by pain.

Here are three unexpected ways that Obama's presidency changed black America.

Change No. 1: Unfriending white America

It was one of the most emotional moments in her life. Kim Coleman was at the Democratic National Convention in Denver in 2008 when Obama accepted the presidential nomination. She called her father, who had grown up in segregated Mississippi, to describe the rapturous scene. And then she wept.

"I had hope running through my veins," she says. "I felt like I was more a part of America."

These are people I've known for years. I was like, 'If you think this about him [Obama], what do you think about me? Linnyette Richardson-Hall, event planner

So did millions of other Americans. Obama's election was described as "unthinkable," a "breakthrough," a "national catharsis." When he gave his acceptance speech before a jubilant crowd at Chicago's Grant Park, America seemed like it had entered The Promised Land. Even people who didn't vote for Obama were moved to tears.

"If there is anyone out there who still doubts that America is a place where all things are possible ... tonight is your answer," Obama said, standing in front of a row of American flags.

Eight years later Coleman is experiencing different emotions: betrayal and shock. She's lost white friends over disagreements about Obama, as well as the issue of police brutality. Even her parents, who used to share dinner and exchange presents with two of their longtime white neighbors, ended those friendships because they felt their neighbors disrespected Obama.

"People I never thought of as racist, people who borrowed money from me -- I've seen things come out of them that I never thought of," says Coleman, who works for a nonprofit in Oklahoma that serves the elderly.

Some black people unfriended white America during Obama's presidency. They would hear a stray remark from a white coworker, argue over something that Obama was facing, and suddenly a close relationship would turn chilly.

Fenise Dunson was a career adviser at an Illinois college in 2008 when some of her white coworkers started warning her about Obama's first presidential run. "We won't let this happen," they said. Or, after he was elected: "He might be president, but you're not in control."

"You don't know where this is coming from," says Dunson, who now teaches at a college in Maryland. She wondered whether "people had been politically correct and they had really been feeling this way for a long time and now they feel like they can be vocal about how they feel?

"It's unsettling. You wonder who you can trust."

Relationships often ruptured over dueling narratives about Obama's opposition. For some people he was being treated the same way as previous presidents -- roughly. President George W. Bush was called a war criminal and compared to a chimp. President Bill Clinton was impeached. President Lyndon B. Johnson was dubbed a "baby killer."

But some blacks saw racial venom in the way Obama was treated. White public figures called him "boy," a "food-stamp president," an "animal" and a "tar baby." One governor wagged her finger in his face. The President was even forced to "show his papers" -- release his original long-form birth certificate -- after "birthers" led by Trump questioned whether he was born in the United States.

Trump's demands that Obama prove his citizenship evoked the slave era when freed blacks were often forced to show their "certificate of freedom" to justify moving freely in public.

Others cite political norms that were violated under Obama. They said no president had been refused a hearing or vote for his Supreme Court nominee since 1875; had a request to address a joint session of Congress rejected by the speaker of the House; or had senators go behind his back to attempt to scuttle his negotiations with another country.

Some blacks found that their friendships with whites couldn't withstand arguments over those controversies. Their suspicion of white people deepened. Richardson-Hall, the event planner, says she unfriended white Facebook friends because of arguments over Obama.

"These are people I've known for years," she says. "I was like, 'If you think this about him, what do you think of me?'"

Change No. 2: Reliving their parents' nightmares

Tucked away in all the tributes to Muhammad Ali was an unusual story about the late boxer's connection to Emmett Till. Till was a black teenager who was tortured and murdered in Mississippi in 1955 for allegedly flirting with a white woman. Till's mother decided to hold an open-casket funeral for her son to force America to confront its racism. Funeral photos of Till's ghastly, disfigured face were branded in the memory of many in that era, including Ali.

"I felt a deep kinship to him when I learned he was born the same year and day I was," Ali said in a PBS documentary. "My father talked about it at night and dramatized the crime. I couldn't get Emmett out of my mind."

Obama was surprised by how racist this country is. Carol Anderson, author of "White Rage"

Imagine Till's death in the age of social media, images of his battered body being shared and tweeted constantly. Now combine that with racist imagery from the Jim Crow era Till lived in -- Sambo dolls with jet black skin and bulbous red lips, blacks eating watermelon -- being spread through popular culture every day.

That's the equivalent of what some blacks say they've been seeing for the past eight years.

Obama presided over the nation during the rise of social media. He came into office just as Facebook, Twitter and other online platforms exploded in popularity. Those tools, though, have resurrected some of the most painful memories of black America.

Google "Obama racism" and you'll see images of Obama being lynched or labeled "Primate in Chief." Michelle Obama was recently depicted by one cartoonist with a penis bulge under her skirt. These are images straight out of America's slave era. And many are not tucked away in ugly corners of the Internet. They are publicly displayed at political rallies and in front of homes.

Open displays of racism have become normal again, some say. More Americans are comfortable publicly expressing racially inflammatory rhetoric, according to some political scientists . Some blacks have noticed. They say they feel like they've been caught in a time warp. They're constantly seeing images and hearing racist language that they thought were relics.

"I thought that all of this nastiness had been litigated and fought by my parents and grandparents," says Richardson-Hall, also a food blogger. "Imagine my surprise, looking at this square in the face."

They're also experiencing something else from the Jim Crow era -- dread of being struck down in public. When a white supremacist shot to death nine worshipers at a South Carolina church in 2015, it evoked memories of the murder of four black girls in Birmingham, Alabama, who died in the infamous 16th Street Baptist Church bombings in 1963.

Richardson-Hall recalls hearing her grandmother tell stories about growing up in South Carolina during the Jim Crow era. She worried about getting lynched or brutalized when she walked in public. When Richardson-Hall read how Trayvon Martin, an unarmed black teenager, was killed while walking home one night because someone thought he was a burglar, she started to feel what her grandmother felt.

"For the first time in my life, I fear something," Richardson-Hall says. "For years, a lot of black people in my position got educated and insulated. We never had to deal directly with what our parents and grandparents did."

The fear has been compounded by the sense that having a black president didn't make any difference. If anything, it made things worse. Anytime Obama publicly empathized with blacks, they say, he was deluged with criticism for playing "the race card."

For Simon, the Emory teaching assistant, that moment of frustration came when Obama was criticized for saying, " If I had a son, he'd look like Trayvon ."

"Here was a moment that some of us in the African-American community had been waiting for to have with Obama, and there were some who didn't want him to do that for us," Simon says. "Why can't we have a relatable moment to the man who is the leader of the free world?"

When I hear we are going to make America great again, I want to say for whom? Fenise Dunson, college instructor

The treatment of Obama hit some blacks like a psychological body blow. It deflated much of the euphoria they felt at Obama's election, according to a New York Times/CBS News poll . In 2008, before Obama was first elected, 60% of blacks said race relations were generally bad. That number fell by half soon after Obama won office. Seven years later, the number had jumped to 68% -- the highest recorded since the 1992 Rodney King riots in Los Angeles.

When the same pollsters asked whether Obama had been treated more harshly because of his race, 80% of blacks said yes, while only 37% of whites agreed.

But it wasn't just the treatment of Obama that made more blacks pessimistic about race. It was what happened during his watch.

"I didn't realize how many people were racist until all of this -- police killings, racism online. It's not just Obama," says Coleman.

And it's not just blacks who have been seething at the treatment of Obama. Some whites have also become troubled by what they've seen and heard -- in some cases from their own relatives.

Lorraine Whittlesey, an artist and composer, says she was surprised to hear a close relative racially insult Obama and declare support for Trump. She's seen social media posts where whites declare that Michelle Obama is a man or that Muslims will take over unless Trump is elected.

"I was astounded by the kind of things that were being said about the President and his family," says Whittlesey, who lives in Baltimore. "People are entitled to their opinion but they were saying that Michelle Obama was a man and their daughters' dresses were too short.

"I still can't believe it's happening. It's an insult to the office of the Presidency."

One black scholar says even Obama was thrown by the reception that greeted him when he became president.

"Obama was surprised by how racist this country is," says Carol Anderson, author of " White Rage ." "He's always been in this space where he was able to negotiate with people who weren't black, to find some middle ground," says Anderson, a professor of African-American studies at Emory. "I think he was kind of knocked off guard."

Change No. 3: He's become 'my brother from another mother'

It may be hard to remember now, but Obama wasn't actually considered the first black president -- Bill Clinton nabbed that honor. Pulitzer Prize-winning novelist Toni Morrison described him that way in a 1998 New Yorker essay

"After all," she wrote, "Clinton displays almost every trope of blackness: single-parent household, born poor, working-class, saxophone-playing, McDonald's-and-junk-food-loving boy from Arkansas."

Obama wasn't a beloved figure in the black community when he first ran for the presidency. Civil rights leaders were slow to warm to him. Others said he wasn't black enough . His mixed-race heritage, exotic upbringing overseas and professorial Ivy League persona didn't fit the traditional black leader mold.

Some black intellectuals said Obama wasn't even African-American because his father was from the east African nation of Kenya.

"Obama isn't black. Black, in our political and social reality, means those descended from West African slaves," Debra J. Dickerson wrote in a 2007 column for Salon magazine

If Obama wasn't black then, he sure is now -- because he's been treated with such racial contempt, some blacks say.

What has happened over the past eight years -- there's no way to unlive or unsee it. Mashaun D. Simon, a blogger and teaching assistant at Emory University

"You hear people say he's dealing with the same things I'm dealing with in life; there's a kinship," says Lauren Victoria Burke, a commentator and political journalist based in Washington who wrote a column in 2012 entitled " The 10 Worst Moments of Disrespect towards President Obama ."

Obama also dropped plenty of cues during his presidency to let blacks know he was part of their tribe.

At a meeting of black journalists, Obama caused his audience to erupt in laughter when he said:

"I want to apologize for being a little bit late. But you guys keep on asking whether I'm black enough. So, I figured I'd stroll in about 10 minutes after the deadline."

There were other black-bonding moments: Obama going falsetto to sing a verse from Al Green's "Let's Stay Together" at the Apollo Theater; breaking into "Amazing Grace" at the eulogy for victims of the Charleston massacre; his love of NBA basketball and hip-hop music.

Some blacks now see themselves in Obama's stride. He doesn't walk with the stiff, chest-thrust-outward, buttocks-clenched-tight stroll of some white politicians. He struts. Michelle Obama calls her husband's walk "swagalicious." Even Trump noticed it. He once tweeted that the way Obama exited Air Force One, "hopping and bobbing," was inelegant and unpresidential.

"He's got that old school bop -- it reminds me of those cats back in the day," says Richardson-Hall, chuckling.

Now, though, black pride in Obama is turning into something else: relief at seeing him go. There were constant worries Obama would not physically survive, a grim thought most preferred to keep to themselves.

"I'm relieved, but it makes me wonder when he gets back in the public world, what does that mean for his safety and the safety of his family?" says Simon, the Emory teaching assistant. "There are people who are still very angry that he was in the White House. When he's gone, that anger just doesn't go away."

What has gone away in the black community are questions about Obama's identity. Go inside many black homes and you'll see the president's picture in the living room right next to a portrait of the Rev. Martin Luther King Jr.

No one is really asking if Obama is black enough anymore.

Is America some fragile thing?

What some people are asking, though, is what happens after Obama's presidency ends. Will the racial divisions of his era continue?

Trump's "Make America Great Again" slogan is seen by some as code for "Make America White Again." Blacks and Latinos have been spit upon and assaulted at some Trump rallies. Trump has a 88% unfavorable rating among blacks; 87% among Latinos.

"When I hear we are going to make America great again, I want to say for whom?" says Dunson, the career adviser who now works at a college in Maryland. "You can almost hear the words, who do you black people, women, Mexican people, Muslim people think you are?"

Many of the groups Trump targets are members of what one political scientist called " The Coalition of the Ascendant " -- racial minorities, millennials, liberal whites. And there are signs that they, too, are angry. A record number of Latinos are registering to vote in some states. Exit polls have found Asian voters shifting increasingly toward the Democratic Party over the last two decades. A majority voted for Republican George H.W. Bush in 1992; 73% supported Obama in the last presidential election.

If blacks saw the rebirth of Jim Crow under Obama, some Latinos saw a rebirth of "Juan Crow" -- the denigration of Latino people and systematic attempts to stifle their political power, says Francisco Ramos, who manages graduate programs at Duke University and writes about multiculturalism and the politics of identity. Ramos says he knows some Latinos who have been Republican since the 1960s but may never vote Republican again.

"The rise of Trump has mobilized Latino voters," Ramos says." Is there room in the current version of the Republican Party for us? I don't think so."

Some now wonder if there is room for them in America's future. Coleman, who works at the Oklahoma nonprofit, says it seemed like the nation had turned a corner when Obama was elected. Now she wonders if that corner led to a dead end.

"I'm a spiritual person. I believe in God. But I don't know if we'll ever see the racial harmony that King talked about," she says. "Sometimes I just feel like we'll never get there."

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That tragic sentiment runs through American history. Racism has been called the nation's "original sin," the "American dilemma." The country fought its bloodiest war over race; its ugliest chapters revolve around race. Its founding documents enshrine equality, while much of its history contradicts those values. Perhaps that is why the late Rev. Vincent Harding, an adviser to King, described America as an idea, not a reality.

"The United States of America is a work in progress -- a shadow on the wall of a multiracial, compassionate democracy that does not yet exist," he once wrote.

Obama has a more optimistic vision of America. Last year he defined American exceptionalism in one of his most memorable speeches, which commemorated the 50th anniversary of the Selma civil rights campaign. He said that "we do a disservice to the cause of justice by intimating that bias and discrimination are immutable, or that racial division is inherent to America."

"We respect the past, but we don't pine for the past," Obama said. "We don't fear the future; we grab for it. America is not some fragile thing."

Obama will soon be gone from office. Will his successor inspire black Americans to recover some of the optimism they lost during the Obama years?

Or will the promise of a compassionate, multiracial democracy that Obama embodies seem like a lie?