By Michael D. Shear, New York Times • Photographs by The New York Times, Pete Souza and Associated PressJANUARY 8, 2017Barack Obama claimed the presidency eight years ago in Chicago's Grant Park, declaring "a new dawn" in American history and promising the enthusiastic crowd of a quarter-million people that "we as a people will get there."

"Because of what we did on this day, in this election, at this defining moment, change has come to America," the new president-elect vowed.

But as the nation prepares to inaugurate Donald Trump on Jan. 20, the bold agenda he described that morning remains incomplete.

What Obama discovered — and what his successor will learn — is that every presidency lasts for only a brief moment in time.

Obama's health care bill gave insurance to millions, but he now faces calls for big changes — or an end — to it. The economy is markedly better, but incomes and growth remain stubbornly low. The immigration overhaul he wanted is tied up in legal limbo, as are his tough new climate rules. Fewer Americans are fighting in overseas wars, but the Islamic State in Iraq and the Levant has emerged as a new threat. Partisanship and racial tensions have intensified.

"There is a lot of unfinished business," said Tom Daschle, the former Democratic Senate leader from South Dakota, a longtime supporter of Obama. "The satisfaction comes in knowing that he has changed the landscape in a very profound way. The frustration comes in knowing what might have been."

Obama entered the White House a living symbol, breaking a color line that had stood for 220 years.

When he took office, race immediately became a focal point in a way that was unprecedented in American history. No matter his accomplishments, he seemed destined to be remembered foremost as the first black man to lead the world's most powerful nation.

But eight years later, Obama's racial legacy is as complicated as the president himself. To many, his election in 2008 was a step toward realizing the dream of a post-racial society.

Blacks, along with Latinos and Asians, voted for him in record numbers in 2008, flush with expectations that he'd deliver on hope and change for people of color.

Some say he did, ushering in criminal justice reforms that helped minorities, protecting hundreds of thousands of immigrants from deportation, and appointing racially diverse leaders to key jobs, including the first two black attorneys general.

These supporters say he deserves more credit than he gets for bringing America back from the worst recession since the Great Depression and the killing of Osama bin Laden. They celebrate his family as a sterling symbol of black success.

But Obama also frustrated some who believe he didn't speak out quickly or forcefully enough on race or push aggressively enough for immigration reform.

And his presidency did not usher in racial harmony. Rather, both blacks and whites believe race relations have deteriorated, according to polls. Mounting tensions over police shootings of African-Americans prompted protests in several cities and the emergence of the Black Lives Matter movement.

Perhaps most strikingly, Trump is seen by many as the antithesis of a colorblind society, a one-time leader of the "birther" movement that spread the falsehood that Obama was born in Africa. Trump's strong reliance on white voters was in sharp contrast to the multiracial coalition that gave Obama his two victories.

Legions of lesbian, gay, bisexual and transgender Americans consider Obama — among all of the nation's presidents — the greatest champion of their rights.

The relationship was slow in developing. Obama took office in 2009 as a self-described "fierce advocate" for gay rights, yet for much of his first term drew flak from impatient, skeptical activists who viewed him as too cautious, too politically expedient. They were frustrated he wouldn't endorse same-sex marriage, but the pace of his actions steadily accelerated. In December 2010, he signed legislation enabling gays and lesbians to serve openly in the military. In 2011, he directed government agencies to combat LGBT rights abuses internationally. By May 2012 — soon after Vice President Joe Biden set the example — Obama endorsed gay marriage.

On June 16, Obama traveled to Orlando to meet with the families of the 49 people killed four days earlier by a rampaging gunman at an LGBT nightclub. Eight days later, he designated the first national monument honoring LGBT rights — the site of the Stonewall Inn in New York City where a 1969 uprising in response to a police raid helped energize LGBT activism nationwide.

In boasting about his tenure in the White House, Obama often cites numbers like these: 15 million new jobs, a 4.9 percent unemployment rate and 74 months of consecutive job growth.

There's one number you seldom hear: More than 1,030 seats. That's the number of spots in state legislatures, governor's mansions and Congress lost by Democrats during Obama's presidency.

It's a statistic that reveals an unexpected twist of the Obama years: The leadership of the one-time community organizer and champion of ground-up politics was rough on the grass roots of his own party. When Obama exits the White House, he'll leave behind a Democratic Party that languished in his shadow and is searching for itself.

When Obama won the presidency, his election was heralded as a moment of Democratic dominance — the crashing of a conservative wave that had swept the country since the Reagan era.

Democrats believed that the coalition of young, minority and female voters who swept Obama into the White House would usher in something new: an ascendant Democratic majority that would ensure party gains for decades to come. The coalition, it turns out, was Obama's alone.

After this year's elections, Democrats hold the governor's office and both legislative chambers in just five coastal states: Oregon, California, Connecticut, Rhode Island and Delaware. Republicans have the trifecta in 25, giving them control of a broad swath of the middle of the country.

The defeats have all but wiped out a generation of young Democrats, leaving the party with limited power in statehouses and a thin bench to challenge an ascendant GOP majority eager to undo many of the president's policies. To be sure, the president's party almost always loses seats in midterm elections. But, say experts, Obama's tenure has marked the greatest number of losses under any president in decades.

"Obama just figured his important actions on policies like immigration and health care would solidify support, but that hasn't really materialized," said Daniel Galvin, a political-science professor at Northwestern University and the author of a book on presidential party building. "He's done basically the minimal amount of party building, and it's been insufficient to help the party."

It's a political reality that Obama has only been willing to acknowledge publicly after his party's devastating November losses. He's admitted he failed to create "a sustaining organization" around the political force that twice elected him to office.

"That's something I would have liked to have done more of, but it's kind of hard to do when you're also dealing with a whole bunch of issues here in the White House," he said at his year-end news conference.

Obama and his aides came into office neither beholden to his party's establishment, nor particularly interested in reinforcing his party's weak spots.

He electrified the 2004 Democratic National Convention with a speech seeking common cause over party differences. Four years later, he defeated Hillary Clinton, the pick of the party insiders, to win the Democratic presidential nomination.

In the White House, Obama's failure to do the typical Washington schmoozing was a constant source of complaint among congressional Democrats, as was his reluctance to endorse down-ballot candidates and inability to parlay Organizing for Action, his grass roots organization, into a significant force.

State parties languished and the Democratic National Committee struggled with dysfunction and debt. "We built this beautiful house, but the foundation is rotten," said South Carolina Democratic Chairman Jaime Harrison, a candidate to lead the Democratic National Committee. "In hindsight we should have looked at this and said, 'Maybe the state parties should be strong.' "

Obama recognized the transient nature of his tenure when he spoke eight years ago to the ecstatic crowd in Grant Park. "Our climb will be steep," Obama said. "We may not get there in one year or even one term."

More recently, he has acknowledged that his legacy will be an incremental one. In an article in the Economist, he described the presidency as "a relay race, requiring each of us to do our part to bring the country closer to its highest aspirations."

Jen Psaki, the White House communications director, said that Obama had always understood that he was part of a continuum. "He recognizes that who he passes the baton to will have a huge impact on whether you build on the progress he made," she said.

White House aides point to what they call the highlights of that progress: digging the country out of a deep economic recession, rescuing the auto industry, extending health insurance to 20 million people, pressing the world to confront climate change, reducing America's combat role in two overseas wars.

But for a president who won the highest office in the land by promising big, sweeping change, the Trump victory was a reminder that it will be up to someone else to complete the change he long envisioned — or undo large chunks of it.

Health care may be the most important example. Passage of the Affordable Care Act in 2010 drastically reshaped the insurance markets in the country, improving access to medical care. But even Democrats agree that much more needs to be done to improve the cost and quality of that care.

"If this was a football field, I'd put us on the 30-yard line with 70 yards to go," said Daschle, who was Obama's first pick for secretary of health and human services but withdrew after questions about his taxes.

Daschle said the unfinished nature of Obama's health care program was partly the fault of Republican obstructionism and partly the result of delays that always occur when trying to overhaul such a large social program. The Affordable Care Act gave Obama's administration great latitude to reshape the nation's health care system, and the president-elect has promised to repeal it and start over.

"That latitude has worked for us," Daschle said. "[In] a Trump presidency, it could work against us."

Climate change, too, remains a work in progress. Internationally, Obama successfully pressed world leaders to aggressively confront the threats from a warming planet. At home, he demanded tougher fuel standards for cars and imposed new regulations on coal-fired power plants.

But the international agreements Obama helped forge will play out over decades. It could be years before his environmental regulations are in place, if ever. It will be up to future presidents to navigate the politics of climate change, around the world and here at home. And Trump has vowed to negate some of those accords and reverse some of Obama's regulations.

"Obama has set the stage for both effective domestic and global climate protection," said Paul Bledsoe, a former climate adviser in Bill Clinton's administration. "But most of the heaviest lifting is going to be done by his successor, especially regarding domestic politics."

Psaki said the fact that large, developing countries like India and China are addressing climate change is "a tremendous step forward" that Obama can claim credit for. "Around the world, a number of countries have cemented their goals. It's not a flash in the pan."

And yet, Obama will have long since left office by the time the United States reaches its deadline to significantly reduce carbon emissions in 2025. And much of the rest of the world has pledged to reach their climate goals by 2030, in the fourth presidential term from now.

Obama concluded his remarks in Grant Park by talking about a 106-year-old black woman, Ann Nixon Cooper, who had cast her ballot in Atlanta. He wondered aloud what changes his daughters would see in America if they lived to be the same age. It was, in a sense, a recognition that the consequences of his time in office would be shaped by others long after he left.

"What change will they see? What progress will we have made?" Obama asked. "This is our chance to answer that call. This is our moment. This is our time."

For Obama, that time is just about over.

The Associated Press contributed to this report.