WASHINGTON — Cory Booker is in.

The New Jersey senator with a celebrity-style profile announced Friday that he is running for the Democratic nomination for president, hoping to challenge President Donald Trump in 2020.

Here, based on years of covering his Senate career and speaking to Democrats in his circle and beyond, are the assets Booker brings to the contest, and the weaknesses that could hold him back.

Why he could win

Optimism and Uplift: “Are there any monuments built to demagogues? I just don’t think so,” Booker told me in 2016. “We’re a nation of hope, of high ideals. I believe we’re a nation of love.”

In a moment of searing division, Booker has tried to make himself into a soothing voice for positivity and uplift. He titled his book United and on his Twitter feed responds to attacks by telling critics he loves them. He talks about a “conspiracy of love” and tells audiences that “if you want to go fast, go alone, but if you want to go far, go together.”

It’s a contrast to the attack-minded president — as well as some of Booker’s Democratic rivals — and a posture that voters might embrace if they are tired of rancor, vindictiveness, and turmoil in Washington.

Booker stressed the positive themes in his campaign launch, with a video that ended in the tagline “Together, America, we will rise.”

Oratory: “If America votes for the best speaker in 2020, they would vote for Cory Booker,” GOP pollster Frank Luntz said in 2017. “He really is that good.” More recently, Philadelphia-based fund-raiser Alan Kessler called Booker “one of the most compelling speakers in the country.”

The senator’s speeches weave together humor, policy, personal anecdotes, and soaring themes. He quotes Martin Luther King Jr., John F. Kennedy, Maya Angelou, and Langston Hughes — sometimes all in the same address.

Booker brings energy and can captivate an audience like few politicians. Some of this works against him (more on that below), but he also has the ability to evoke passion, which is no small thing.

A fresh face: Booker, 49, would check two biographical boxes among Democrats: he would bring the generational shift many liberals crave and he reflects the party’s increasingly diverse base.

One of his political skills is his ability to blend into numerous settings. Booker was raised in the suburbs but lives in a largely minority city. He’s African American, speaks Spanish, and can throw in some Yiddish (he became copresident of a Jewish organization at Oxford). One of his first interviews after announcing his candidacy was with the Spanish-language network Univision. He quotes Bible verses to more conservative audiences.

And Booker is fluent in social media, one of the first politicians to expansively use Twitter, even before Trump made it his primary communication platform. In other words, Booker embodies the cosmopolitan makeup of the Democratic Party.

Fame: Booker has a reach that extends beyond the political world and into pop culture.

He was featured in a documentary, Street Fight; frequently appears on late-night comedy shows; has been on Oprah and The View; and even showed up in cameos on comedies like Parks and Recreation.

None of that by itself makes him qualified to be president, but in a crowded field where there may be more than two dozen candidates, having a recognizable name won’t hurt. Just look at how Trump plowed through the crowded GOP field in 2016.

How he could fail

Optimism and Uplift: Many of Booker’s strengths can also cut against him.

His optimistic message might work on people tired of the fighting in Washington, but many Democrats don’t want conciliation. They want to fight fire with fire.

They see a president threatening tearing down vital institutions and norms, and threatening to change the country’s character. And many believe the political and economic systems are controlled by insiders, and want their own flamethrower to take a torch to it.

That’s partly why firebrands such as Bernie Sanders and Elizabeth Warren and, from a different perspective, Trump have thrived. Booker’s message of unity could end up off the mark in such a moment of social strife.

"I’m running, really, not to beat anybody, I’m running to unite people,” Booker said in one radio interview Friday.

A crowded lane: Booker isn’t the only younger face in the race. He’s not the only senator, or the only African American, or even the only African American senator. He’s not the only one calling for unity and togetherness.

So how does he stand out?

Booker would likely point to his time as a mayor, when he ran a city government rather than just serving as a legislator. He’ll undoubtedly point to the economic developments, expansions of parks, and other gains that began on his watch. But he’ll still face a challenge in distinguishing himself.

He and Sen. Kamala Harris, of California, in particular, have such similar profiles they could end up competing for the same slice of the primary electorate. Both are relatively young, black senators with uplifting messages and connections to struggling cities. They are likely to compete most intensely in South Carolina, the third state to hold a primary nominating contest and the first with a significant African American population. It’s no coincidence that the Palmetto State is one of the first two Booker will visit as a candidate.

Corporate Cory? Booker is on the left of nearly every major policy debate: He opposed the GOP tax cuts, fought to protect the Affordable Care Act, helped organize a push to pass new gun laws, and was one of the leading advocates for the recently approved bill easing federal prison sentencing. Name a social issue, and he sides with liberals.

Yet he still draws skeptical looks, and sometimes outright hostility, from some liberals.

Many believe he is too close to Wall Street and pharmaceutical companies, both of them big employers in his home state. They remember his defense of “private equity” during the 2012 presidential election, when Barack Obama was hammering Mitt Romney’s Bain Capital as a predator.

Booker is also tight with Silicon Valley and in Newark championed charter schools, teaming up with Republican Gov. Chris Christie and Facebook’s Mark Zuckerberg in a high-profile move that drew intense scrutiny and criticism from the city’s teachers’ union.

Booker has tried to combat some of these perceptions, saying he refuses money from corporate political committees (though not individual executives) and he is teaming up with Sanders on bills to lower prescription-drug costs.

“Spartacus” moments: Booker’s passion is part of his appeal. But he can go overboard.

He drew ridicule for saying (out loud), “This is about the closest I’ll probably ever have in my life to an ‘I am Spartacus’ moment” after fellow Democrats supported Booker’s release of already-released documents at a confirmation hearing on Supreme Court Justice Brett Kavanaugh. His earlier comment implying that Kavanaugh supporters were “complicit in evil” became a central GOP talking point as they argued that Democrats had become unhinged. (The full quote: “In a moral moment, there is no bystanders. You are either complicit in the evil, you are either contributing to the wrong, or you are fighting against it.”)

From Hillary Clinton’s “basket of deplorables” to Romney’s “corporations are people” to Barack Obama’s comment about how some small-town people “cling to guns and religion,” verbal miscues can assume an exaggerated role in campaigns, often reinforcing critics' worst fears.

National Republicans on Friday bashed Booker as “a disingenuous self-promoter” and on The View host Meghan McCain pressed Booker on how he can convince people he’s “not phony.”

“You’ve got to be who you are,” Booker replied.

Newark scrutiny: There’s no question that Booker’s tenure as mayor of Newark saw progress in the city. But it didn’t go as far as some might depict.

Unemployment, crime, and poverty remained stubborn.

It was a mixed bag that will likely come under the microscope. Newark was struggling for decades before Booker was mayor, and continues to wrestle with significant challenges. Fairly or not, Booker will have to answer for many that predated him and that remained after his time in charge.

Where’s the substance? Booker’s big public persona has been shadowed by a concurrent question: Is there enough depth there?

Inside New Jersey political circles, some have derisively called him “Senator Kardashian,” implying that Booker is more hype than substance. The same oratory that rouses some strikes others as a vapid collection of inspirational phrases.

A presidential campaign could put more scrutiny on the policies behind Booker’s words and test whether he can back up powerful rhetoric with nuts-and-bolts policies.