NEWARK — Drawing on themes from the Rev. Dr. Martin Luther King Jr.’s “Letter From a Birmingham Jail,” Senator Cory Booker pitched his campaign for president in newly urgent terms on Saturday, declaring that “we are here today to say we can’t wait” as he laid out his vision for addressing the economic and social ills of the country.
In what was billed as the major hometown rally kicking off his campaign, Mr. Booker spoke to a late-arriving but enthusiastic crowd at Military Park, a revitalized green oasis in a city that was once a symbol of urban despair but has credible claims of an economic and cultural resurgence. Mr. Booker combined his familiar themes of unity with specific policies to close the racial wealth gap, repair what he considers a broken criminal justice system and set the country on a path to be a leader in climate change.
“We can’t wait when powerful forces are turning their prejudice into policy and rolling back the rights that generations of Americans fought for and heroes died for,” Mr. Booker said. “We can’t wait when this administration is throwing children fleeing violence into cages, banning Muslims from entering the nation founded on religious liberty, and preventing brave transgender Americans from serving the country they love.”
The event also marked a kind of apex of Mr. Booker’s focus on Newark, a city he mentions more often on the campaign trail than his own name, hoping that the city’s rocky yet resilient rise can help propel him to the top of a crowded Democratic field for the 2020 election.
In a race that features six senators, Mr. Booker has often sought to shift the focus from his time in Washington to his tenure in what is known as Brick City, when he was a young, upstart mayor who quickly achieved celebrity status for his well-documented and social-media-fueled efforts to turn around Newark.
“There is nobody in this race who has been a chief executive officer of their state’s largest city managing through a recession,” Mr. Booker told crowds in New Hampshire last weekend.
But it is a pitch that is not without risk.
While Newark, which has a population of 285,000, is clearly in the midst of a revival, it still struggles with crime and poverty. The median household income is roughly $20,000 less than the national average, and more than 28 percent of the city’s residents live below the poverty line, according to the United States census.
And Mr. Booker’s tenure in Newark was not without blemishes. The Police Department, plagued by decades of mismanagement and corruption, was investigated by the Department of Justice and placed under a consent decree. The results were mixed for a highly touted $100 million investment in Newark schools by Mark Zuckerberg, the chief executive of Facebook. And though homicides reached historic lows early in Mr. Booker’s first term, crime began to tick back up just as he was elected to the Senate in 2013, eliciting criticism that he had stopped focusing on the city with his sights set on Washington.
Ras Baraka, the current mayor of Newark, was one of those critics. But he has since reconciled with Mr. Booker, and the two have united around a message of progress sparked by Mr. Booker and brought across the finish line by Mr. Baraka (his re-election slogan last year was “Touchdown!”).
“If you make your bones here, there is no place out there that can stop you in this country,” Mr. Baraka said, referencing Newark. “I usually tell people he got us on the field, and we took the ball and got us in the end zone. But if you can’t get in the game, you don’t get to win the championship. Senator Booker got us in the game.”
Amid the crowd on a surprisingly hot April afternoon, Mr. Booker basked in the city’s renewal, as evidenced by the street vendors lining the park and the long shadows cast by skyscrapers, both venerable ones and new glass towers bearing the logos of Fortune 500 companies.
“When this city took a chance on me as their mayor, the chief executive of this city, I didn’t wait to bring people together,” Mr. Booker said. He continued, “We got people to invest here. We opened new businesses, created thousands of new jobs and after 60 years of decline, Newark is growing again.”
Mr. Booker began his campaign for president with a video from the streets of the city he still calls home, and his campaign swings feature the near ubiquitous campaign line of “I got my degree at Stanford but my Ph.D. on the streets of Newark.” But he ratcheted up his focus on Newark in the weeks before the rally.
In a recent campaign swing through New Hampshire, Mr. Booker recalled his much-publicized battle with Conan O’Brien, who as host of “The Tonight Show” in 2009 joked that a better health care plan for citizens of Newark “would consist of a bus ticket out of Newark.” Mr. Booker responded by recording a video “banning” Mr. O’Brien from the city’s international airport. The tiff played out for weeks on social media and late-night shows, before Hillary Clinton stepped in to broker a peace deal.
Mr. Booker, who critics sometimes charge chased fame more than his mayoral duties, paints the whole affair as a clever bit of earned publicity for his struggling city.
“That video went viral,” Mr. Booker told a crowd at a house party in Bedford, N.H., last week. “Every show I was going on — I went on Jay Leno — every chance I had I talked about the opportunities in Newark. I bragged about my city with more American eyes watching than ever before.”
Leading up to Mr. Booker’s address was a cattle call of influential New Jersey Democrats, including Gov. Philip D. Murphy, Senator Robert Menendez, Mr. Baraka and Joseph N. DiVincenzo Jr., the Essex county executive.
But as much as his home state and city were represented at the rally — even the marching band from his launch video took the stage to warm up the crowd before Mr. Baraka spoke — Mr. Booker continued to focus on a sense of critical national urgency.
In choosing to have his kickoff rally on April 13, Mr. Booker pointed to the same day in 1969, when Dr. King first woke up in a jail in Birmingham and began writing what would become the “The Letter from Birmingham Jail.”
“Generations of Americans have shown us what was possible when they refused to wait,” Mr. Booker said. “Now it’s our turn. And we have work to do.”