WASHINGTON — New Jersey Sen. Cory Booker launched his campaign for president on Friday, offering a message of uplift and unity as he joined a crowded Democratic field on the first day of Black History Month.

Booker, who rose to national attention as the mayor of Newark, has long presented himself as a healer for divided times, delivering soaring speeches that often quote the Rev. Dr. Martin Luther King Jr., Mohandas K. Gandhi, and other inspirational leaders. He evoked those same themes in an introductory video that blended scenes of the senator walking through Newark with images of civil rights marches.

“Together, we will channel our common pain back into our common purpose,” Booker, 49, said in his video.

He elaborated on the idea in several media appearances throughout the day.

“We live in a nation where people are beginning to lose faith in what we can do together,” he told the Tom Joyner Morning Show. “I’m running for president to change that, to reignite our sense of what’s possible, and reignite the moral imagination of what we can become together.”

In the video, emailed to supporters and posted on Twitter, Booker talks of “collective action" and “interwoven destinies of slaves and abolitionists, of those born here and those who chose America as home.”

The montage does not mention President Donald Trump, though it calls for a country "where we see the faces of our leaders on television and feel pride, not shame.”

His message — punctuated by the tagline “together, America, we will rise” — presents a pointed contrast to Trump, some of the more pugilistic Democrats already in the race, and an atmosphere of political rancor.

But his conciliatory tone may fall flat among Democratic voters hoping for a fighter to aggressively take on the president.

“I’m running, really, not to beat anybody, I’m running to unite people,” Booker said in his first radio interview.

After his announcement Friday, Booker appeared on The View and did three call-in interviews with radio and TV shows that focus on African American or Hispanic audiences, including one with Spanish-language network Univision, a sign of his efforts to build cross-cultural appeal. Booker, who answered questions in Spanish, is seeking to become the second African American president.

He plans to quickly visit the three states holding the first primary nominating contests, with a trip to Iowa and South Carolina scheduled for Friday to Feb. 11 and a visit to New Hampshire the following weekend.

“I get the sense that what he wants to become is the conscience of America, if you will,” said John Brabender, a Republican media strategist based in Virginia. “I listen to his speeches, and they sound more like a movement of what America can be.”

The Republican National Committee blasted Booker as “totally out of touch with most Americans” and a showman, not an effective leader.

“Cory Booker is a political opportunist who left Newark ridden with crime and an ‘emblem of poverty,’ " said a statement from committee spokesperson Michael Ahrens. “Even the liberal base thinks he’s a disingenuous self-promoter.”

Booker’s main appeal has long centered on his biography, his upbeat and gregarious persona, and his talent for drawing attention to himself and causes he supports. He once, for example, ran into a burning home to rescue a Newark woman. His first run for mayor, in 2002, was featured in the documentary Street Fight, and he was later the focus of a TV series called Brick City.

Those personality traits and viral moments have made him a quasi-celebrity with a following that includes the likes of Oprah Winfrey and Steven Spielberg. In 2016, he was a finalist to become Hillary Clinton’s vice presidential nominee, and spoke in prime time at the Democratic National Convention in Philadelphia.

>> READ MORE: Amid rancor, Booker strikes a healing note

Booker was one of the earliest politicians to cultivate a significant following on social media, is a regular on late-night comedy shows, and has even landed cameos on sitcoms.

“Before there was a Donald Trump, there was Cory Booker on Twitter,” said John Lapp, a Democratic media strategist who has worked on past presidential campaigns.

In his first Senate term, Booker has compiled a liberal voting record, focusing frequently on racial and social justice.

He played a leading role in the bipartisan push that recently reformed federal criminal sentencing rules, and in the run-up to his campaign, he introduced a series of bold, and likely expensive, proposals, including a federal jobs guarantee and an investment plan to provide every newborn with a taxpayer-funded savings account. He has cosponsored the Senate bill to provide Medicare to all Americans, an idea that has become a political litmus test for Democratic primary contenders.

Booker, however, said Friday that he would not seek to eliminate private health insurance, drawing a contrast with one primary rival, Sen. Kamala Harris (D., Calif.), who embraced that as an option.

“He is very progressive on some issues, but of course progressives don’t entirely trust him.”

Former Pa. Gov. Ed Rendell

Throughout his rapid rise, Booker has been trailed by questions about whether he has the substance to back up his flashy profile, and some critics see his speeches as overwrought and empty.

He drew conservative mockery last year when he compared himself to Spartacus during a Senate hearing on Supreme Court Justice Brett Kavanaugh and suggested that those who backed the nominee were “complicit in evil.”

On The View, host Meghan McCain asked Booker how he would convince people he’s “not a phony.”

“You can’t speak to authenticity. You’ve got to be who you are all the time,” Booker replied, arguing that he should be judged on his work.

Some liberal activists, meanwhile, have questioned Booker’s ties to Wall Street and Silicon Valley, and his support for charter schools, which he turned to in a controversial overhaul of Newark’s public school system.

“He is very progressive on some issues, but of course progressives don’t entirely trust him,” said former Pennsylvania Gov. Ed Rendell.

In a Democratic primary, Booker could represent the generational change many younger voters crave, and he reflects Democrats' increasingly diverse coalition. But he will have to contend with a broad spectrum of competitors, including other well-known senators such as Harris; Elizabeth Warren (D., Mass.); and, likely, Bernie Sanders (Ind., Vt.), along with numerous other candidates already in the race or considering it.

Booker and Harris are close in age, are both telegenic presences, and have each tried to focus on togetherness. They are likely to battle for the support of black voters, particularly in South Carolina, the first Democratic primary state with a large African American population. That contest is expected to be vital to both of them.

“He’s got extremely strong credibility and authenticity among African American voters, so it makes sense to go after that group," said Patrick Murray, director of the Monmouth University Polling Institute, which recently finished a national poll that included 19 Democrats who are running for president or who might run.

Booker was raised in the affluent New Jersey suburb of Harrington Park after his parents took part in a sting to expose Realtors who refused to sell to black buyers, a fight he credited with paving the way for his future. Booker graduated from Stanford University, Yale Law School, and Oxford University, and drew national notice by then moving into a housing project in Newark.

He held his final public event of the day on the stoop outside his modest townhouse, stressing that he is the only senator who lives in a low-income, largely minority community.

Despite the widespread attention, Booker left a mixed record in Newark, where economic development rose, but so did poverty during a tenure that overlapped with the Great Recession. Booker has faced questions about his ability to match his big ideas with the follow-through needed to deliver.

His organizational ability will likely be tested in a grueling primary.