Watch President Obama’s full speech at the Democratic National Convention on July 27. (Video: The Washington Post; Photo: Michael Robinson Chavez/The Washington Post)

President Obama takes the stage at the Democratic National Convention on Wednesday for what aides said he views as a symbolic passing of the mantle after eight years as the leader of the Democratic Party.

Obama burst onto the national political scene with a soaring address 12 years ago to the day at the 2004 convention, and he was the center of attention as the nominee in both 2008 and 2012. But the president gave clear instructions to his team as it began envisioning this speech a month ago: It was not to be a valedictory for his White House tenure or a direct rebuttal to Republican nominee Donald Trump.

Rather, the president told his advisers, he wants to make the most forceful case possible for Hillary Clinton as the best qualified public servant to succeed him.

He is expected to tout Clinton’s experience in the White House: “Until you’ve sat at that desk, you don’t know what it’s like to manage a global crisis or send young people to war,” Obama is expected to say, according the his prepared text. “But Hillary’s been in the room; she’s been part of those decisions. She knows what’s at stake in the decisions our government makes for the working family, the senior citizen, the small business owner, the soldier, and the veteran.”

And in a moment of particular modesty, he is expected to essentially concede that she is better prepared for the job than he was. “. . . No matter how much people try to knock her down, she never, ever quits. . . . That’s the Hillary I know. That’s the Hillary I’ve come to admire. And that’s why I can say with confidence there has never been a man or a woman more qualified than Hillary Clinton to serve as president of the United States of America.”

The speech is just the beginning, aides promise.

“We’ll do everything we can to help her,” a senior administration official said during a background briefing for reporters to preview Obama’s address. “From this point forward, she is the torchbearer of the Democratic Party.”

White House officials said the president and his advisers labored through six drafts of his remarks during the past week. Obama stayed up until 3:30 a.m. to work on the speech after his wife, first lady Michelle Obama, delivered her rousing convention address Monday. Aides suggested that there may have been a touch of spousal competitiveness at play.

The president then needed just a single dry run, reciting the 30-minute speech out loud in the Map Room on Tuesday, before pronouncing himself satisfied. Obama aides contacted the Clinton campaign this week to offer them a summary of the address.

In an interview with NBC’s “Today,” Obama urged the party not to take the November election for granted, and he said of a possible Trump victory that “anything is possible.”

“I think anybody who goes into campaigns not running scared can end up losing,” Obama said. “So, my advice to Democrats — and I don’t have to give this advice to Hillary Clinton, because she already knows it — is you stay worried until all those votes are cast and counted because you know, one of the dangers in an election like this is that people don’t take the challenge seriously. They stay home. And we end up getting the unexpected.”

In many ways, the White House views Obama’s speech as the kickoff to his role as surrogate in chief, and they said he will stump enthusiastically for Clinton in the final months before the Nov. 8 election — raising money, doing robo-calls and appearing at rallies in key swing states.

Post political reporters Dan Balz, Robert Samuels and Abby Phillip and senior political editor Steven Ginsberg held a town hall conversation at the Democratic National Convention, giving a behind-the-scenes look at covering 2016. (Washington Post Live)

“He wants to be one of the loudest voices out there making the case for why she is the right person to succeed him,” said another senior White House official.

Obama, who is scheduled to be in Philadelphia for less than two hours, will speak after remarks by former New York City mayor Michael Bloomberg and Vice President Biden.

An eight-minute video highlighting the nation’s progress during the president’s tenure — featuring appearances by Biden, Michelle Obama, senior adviser Valerie Jarrett and former adviser David Axelrod — will be shown before the president speaks, aides said.

In a moment that will highlight the solemn responsibilities of the commander in chief, Obama will be introduced by Sharon Belkofer, 73, a retired nurse and school board member in Rossford, Ohio, who has met the president twice before. Belkofer’s three sons served in the U.S. armed forces, and one, Lt. Col. Tom Belkofer, was killed in a Taliban attack in Afghanistan in 2010.

The president intends to make the case for Clinton by focusing on her experience as a public servant, having worked closely with her when she served as U.S. secretary of state during his first term. As he did in a joint campaign appearance with Clinton in North Carolina this summer, the president will sketch the arc of their relationship, evolving from fierce competitors for the 2008 presidential nomination to close working partners.

Aides said the president will mention Trump a half-dozen times, but Obama does not intend to dwell on the GOP nominee despite having denounced his positions on immigration, counterterrorism and Muslim refugees, among other issues.

At heart, Obama does not believe he must offer a detailed policy rebuttal to Trump, aides said, because Trump’s rise and rhetoric have raised broader questions of the nation’s moral values and the temperament of the candidates to become commander in chief.

“What I think is scary is a president who doesn’t know their stuff and doesn’t seem to have an interest in learning what they don’t know,” Obama said of Trump on “Today.” “I think if you listen to any press conference he’s given, or listen to any of those debates, basic knowledge — about the world or what a nuclear triad is or where various countries are or, you know, the difference between Sunni and Shia in the Muslim world — those are things that he doesn’t know and hasn’t seemed to spend a lot of time trying to find out about.”

The president also plans to use the speech to offer praise for Sen. Bernie Sanders (Vt.), who waged a fierce primary campaign against Clinton and whose delegates have remained vocal in their support for him at the convention even as he has urged party unity. Obama called Sanders on Tuesday to congratulate him after the senator moved on the convention floor to nominate Clinton by acclamation. Aides said the president will emphasize the success Sanders had in inspiring passion in younger voters.

Though aides said the president is intent to not make the speech about himself, they said he will hark back to his famous address from the 2004 Democratic convention, during which he urged the nation to rise above partisan politics and find common ground.

Obama will touch on those themes again in Philadelphia, aides said, and though he has acknowledged that the partisan tenor in Washington has not improved, the president will reaffirm his view that the American people have more in common than they do differences and that the nation is stronger together than apart.