Cory Booker may have just given his most powerful 2020 speech yet after a sleepy start to his campaign

Chris Aluka Berry/Reuters

Sen. Cory Booker talks with Rev. Jesse Jackson, before giving the keynote speech at Brown Chapel AME Church in Selma, Alabama, on March 3, 2019.

• Sen. Cory Booker on Friday got a standing ovation at the end of his speech at a civil rights conference in New York City.
• The speech was perhaps Booker's most successful performance yet along the 2020 campaign trail as he's struggled to pull ahead of other Democratic candidates.
• "It's time for us to dream again. And if we join arms again, and work together, and sacrifice together, and dream together - then we will finally be a nation where justice rolls down like water and righteousness like a mighty stream," Booker said to a cheering audience. "Keep the dream alive!"

NEW YORK CITY - Sen. Cory Booker had the crowd on their feet at the end of his speech at the National Action Conference in midtown Manhattan, delivering perhaps his most effective 2020 performance yet.

The conference, which was held by Rev. Al Sharpton's organization, had a heavy focus on civil rights.

While recalling a time his brother took him to the Memphis, Tennessee, hotel where Dr. Martin Luther King Jr. was assassinated, Booker said, "Yesterday was April 4th - the 51st year since the assassination of Martin Luther King ... We are the inheritors of a generation who marched for us. Who on that Edmund Pettus bridge got beaten and bled for us. We are inheritors of a generation that just trying to register people to vote can get you killed ... We are here standing on the shoulders of giants. Folks on my block don't want sentiment, they want substance."

Read more: Bernie Sanders said he'd sign a bill to research reparations for descendants of slaves if elected president

The senator went on to say, "I boldly proclaim to you that it's time my generation - it's time for us to dream again. Bold dreams and defiant dreams. It's time for us to dream again, that we can be a nation where everyone has access to health care. It's time for us to dream again, where every child will have a great public education regardless of their zip code. It's time for us to dream again, where everyone who works a full-time job will have a living wage for their families."

Invoking King, Booker added: "It's time for us to dream again. And if we join arms again, and work together, and sacrifice together, and dream together - then we will finally be a nation where justice rolls down like water and righteousness like a mighty stream. Keep the dream alive!"

Booker's critics have often accused him of speaking in platitudes too often rather than focusing on specific, substantive policies. He's frequently been deemed "inauthentic" as a consequence.

But his speech on Friday was a synthesis of in-depth discussion on policy and the impassioned, lofty rhetoric for which Booker has long been known. Booker touched on a broad array of issues, offering his thoughts on everything from marijuana legalization to reparations for descendants of slavery.

Polls have shown the New Jersey senator trailing way behind other 2020 candidates like Sen. Bernie Sanders, Sen. Kamala Harris, and former Rep. Beto O'Rourke. Unlike Sanders and Harris, among others, Booker also hasn't released fundraising numbers and it's not clear how he's doing compared to the rest of the 2020 field.

Read more: Cory Booker kicked off his 2020 presidential campaign by calling for legal marijuana

In short, Booker's 2020 campaign has struggled to gain momentum so far as lesser-known politicians like South Bend Mayor Pete Buttigieg rise in prominence and garner lots of media coverage.

But Booker may have done better to win over the crowd than any of his challengers who've spoken at the conference this week, which included Sanders, Harris, and O'Rourke.

At the end of Booker's speech, the room was electric as the crowd gave him a standing ovation. Simultaneously, civil rights icon Rev. Jesse Jackson, who was sitting nearby, stood up and held up Booker's hand as if he was a boxer who just won a championship fight.