Sen. Cory Booker of New Jersey said Friday that he will seek the Democratic nomination for president, adding his name to a growing and increasingly diversified field of 2020 candidates intent on taking on President Trump.

Booker made his announcement via video Friday morning. He also spread the news through a round of interviews and at an afternoon conference outside his house in Newark, where he reiterated his intention to run a campaign “not just to beat the Republicans but to unite Americans.”

His news conference, which he interrupted to call out “hermana” to a neighbor watching across the street, included numerous references to his efforts as mayor of Newark. It also included much of his signature rhetoric about the power of love to overcome society’s most troublesome issues.

“We used to be a people who could look at the sky, point at the moon and change it from a dream to a destiny,” Booker said. “There’s no Democratic or Republican way to get there. You definitely don’t get there by fighting each other, tearing each other down or dividing people against each other.”

Booker joined a field that already included three other senators — Kamala D. Harris of California, Elizabeth Warren of Massachusetts and Kirsten Gillibrand of New York — as well as several other candidates. He was immediately called upon to differentiate himself from his colleagues.

Harris made headlines earlier this week when she said she would be in favor of doing away with private health insurance as part of transitioning the country to Medicare-for-all. Booker was asked if he would do away with private health care.

“Even countries that have vast access to publicly offered health care still have private health care,” Booker said. “So, no.”

In a midday interview on ABC’s “The View,” Booker said his campaign would be distinguished from other campaigns by his entree into politics and his continued residence in Newark.

“They’re going to see a very different, not usual path,” he said of voters.

Booker also emphasized his past work to lessen incarceration rates and criticized the president’s border policy, particularly the decision to separate young children from their families.

“This is a moral vandalism on the ideals of our country,” he said.

Who is running for president in 2020?

Like many of his fellow Democratic candidates, Booker — who has received corporate PAC money in the past and criticism from those on the left and right for his close ties to Wall Street and Silicon Valley donors — declared he will not accept corporate PAC money for his campaign.

Booker’s decision to run did not come as a surprise. He has been traveling to early-voting states for months, teasing his eventual entrance. On Martin Luther King Jr. Day, he visited South Carolina, the first of the early-voting states in which black voters dominate.

That same day, Harris announced that she was running for president. Booker also played into symbolism, joining the race on the first day of Black History Month, a fact he noted on “The View.”

Booker’s entry makes this the first nomination contest with at least two major African American contenders. Former attorney general Eric H. Holder Jr. is also considering a run.

Booker’s announcement came toward the close of a week that raised the prospect of a significantly more complicated 2020 campaign. Howard Schultz, the former chief executive of Starbucks, confirmed on CBS’s “60 Minutes” that he was considering an independent run for the presidency.

While Schultz, a billionaire, argued that both major political parties were broken — and he plans to spend lavishly to make his point — Booker implicitly defended the Democratic Party and its policy priorities.

Booker, 49, has been looked at as a potential presidential contender for most of his political life. In 2002, when he made his first, unsuccessful bid for mayor, he was followed by reporters and documentary crews; a chronicle of the campaign, “Street Fight,” was nominated for an Academy Award. Four years later, Booker ran again and won by a landslide.

From City Hall, Booker became one of the country’s best-known mayors, leveraging his fame into attention and lucrative investments for Newark. Months after taking office, the digital audio start-up Audible moved its headquarters to Newark. Months after Booker won a second term, Facebook founder Mark Zuckerberg plowed $100 million into a fund to improve the city’s schools.

The mayor found plenty of critics, who argued that his effervescent Twitter presence and willingness to visit constituents at their homes masked persistent problems with public services. In 2012, Booker angered liberals by criticizing President Barack Obama’s attacks on Republican presidential nominee Mitt Romney, saying that painting Wall Street with “broad brushes” was unfair to “the good people who work there.”

But in 2013, when the death of Frank Lautenberg opened one of New Jersey’s U.S. Senate seats, Booker zoomed through a special election and won easily, with a donor list that included Ivanka Trump. Booker was the first black Democrat to join the chamber since Obama had left it, and he quickly established himself as a business-friendly liberal.

After winning a full term in 2014, Booker began to make moves on the left. He broke with Sen. Robert Menendez (D-N.J.) to back Obama’s nuclear deal with Iran and helped protect states that had legalized medical marijuana.

In 2016, Sen. Bernie Sanders (I-Vt.) quietly vetted Booker as a potential running mate. In 2017, Booker endorsed Sanders’s Medicare-for-all heath-care plan, as well as legislation to raise the minimum wage to $15 an hour.

Despite that, Booker has been viewed skeptically by his party’s left and been ridiculed by conservatives, who say his image has been carefully manufactured.

Booker is the rare bachelor to seek the presidency; none has been elected since 1856.

In his announcement video sent to supporters, Booker talked of his upbringing in New Jersey, one that he noted distinguishes him from the rest of the Senate — as well as his competitors in the presidential race.

“When I was a baby, my parents tried to move us into a neighborhood with great public schools, but Realtors wouldn’t sell us a home because of the color of our skin,” he said. “A group of white lawyers, who had watched the courage of civil rights activists, were inspired to help black families in their own community, including mine. And they changed the course of my entire life. Because in America, courage is contagious.

“My dad told me, ‘Boy, never forget where you came from or how many people had to sacrifice to get you where you are.’ ”