When Cory Booker arrived in Washington, he dined with Ted Cruz, talked criminal justice reform with Rand Paul, and tried to make good on a campaign pledge to pursue common ground and choose "pragmatism over partisanship."

Times have changed, and now the first-term New Jersey Democrat and former Newark mayor — who built his political brand on positivity and the power of love — has put on the gloves. As the nation tunes in to the confirmation hearings for Judge Brett Kavanaugh, President Trump's nominee for the Supreme Court, Booker has at times adopted a confrontational approach likely to resonate with a resistance-fueled Democratic base.

On Tuesday, he helped Democrats blow up the comity often associated with the Senate Judiciary Committee: interrupting the committee chairman, declaring the process "absurd," hoping to sink the nomination, or at least delay proceedings until more records from Kavanaugh's background are released.

Republicans said that the Senate had enough documents and that a number of Democrats, including Booker, had already announced their opposition to Kavanaugh.

"What is the rush? What are we hiding by not letting those documents come out?" Booker said near the start of Tuesday's hearing to Sen. Charles Grassley (R., Iowa), the committee chairman. Appealing to Grassley's "sense of fairness and decency," Booker said: "Sir, this committee is [in] violation of the values that we as a committee have striven for: transparency."

The chairman accused Booker of "taking advantage of my decency and integrity."

The televised confirmation hearings come as Booker considers a presidential bid in 2020, when he'd need to win over a Democratic primary electorate that has demanded defiance of Trump.

Many Democratic activists are seething with anger, and it isn't clear they'd be satisfied with Booker's lofty talk of Maya Angelou and Gandhi.

The battle over the direction of the Supreme Court is particularly frustrating for Democrats, who accuse the GOP of stealing a seat from former President Barack Obama by refusing to consider his chosen replacement for Justice Antonin Scalia, who died in 2016.

Trump replaced Scalia last year with the conservative judge Neil Gorsuch.

Kavanaugh, a federal appellate judge in Washington who is likely to be confirmed by the Republican-controlled Senate, would replace Justice Anthony Kennedy, a Reagan appointee long seen as the court's swing vote.

His appointment could cement a conservative majority on the court for a generation, and influence health care, abortion rights, voting rights, labor laws, and more; the judge also could have a potentially decisive role in the investigation of Trump. Kavanaugh has written about his skepticism of such inquiries.

"It seems so clear that in your court the same folks seem to win over and over again: the powerful, the privileged, big corporations, special interests," Booker told the judge Tuesday during opening statements. "This is why so much is at stake."

On Wednesday, Booker got another bite at the apple, as each senator was getting to question Kavanaugh at length.

Booker wanted to ask about an email during Kavanaugh's time in the Bush White House that the senator said showed Kavanaugh was at least open to racial profiling by police. Booker said he was limited in his questioning because the email was labeled "committee confidential" — available to senators but not the public. He called for the email's release.

Republican senators, without naming individuals, have accused Democrats of protesting with an eye on their 2020 presidential ambitions. Booker, Sen. Kamala Harris (D., Calif.), and Sen. Amy Klobuchar (D., Minn.) all participated in the verbal fireworks, and all are seen as potential candidates. Some conservatives took umbrage with an email Booker sent to supporters during the hearing that looked like a fund-raising solicitation.

Cruz, a Texas Republican on the Judiciary Committee, said the Democrats' push to delay was really about "trying to relitigate the 2016 election and just as importantly, working to begin litigating the 2020 presidential election."

Other Republicans pounced on Booker's suggestion in July that those who support Kavanaugh were "complicit in evil" — evidence, they said, of Democratic derangement.

But Booker won praise from some in his party pushing for a more aggressive posture.

"I think it's great that Booker's standing up, and Democrats are playing it right," said former Vermont Gov. Howard Dean, who ran for president in 2004. Dean called the Kavanaugh nomination a "travesty."

"I think he's been pretty much on fire for a year or two," Dean in an interview said of Booker.

In the weeks leading up to the hearings, some liberals had been underwhelmed by their party's seeming resignation to the inevitability of Kavanaugh's confirmation. Even though the GOP majority is slim, some Democratic senators running for reelection in states Trump won in 2016 are under pressure to back the nominee.

As Grassley gaveled in the start of the hearing Tuesday, Harris immediately moved to postpone it. Protesters repeatedly interrupted, were arrested and hauled away. And Democrats warned that because Kavanaugh has written that presidents should be exempt from prosecution while in office, his confirmation could effectively shield Trump from the special counsel investigation.

Booker's role in the fray followed other recent moments of intense opposition from the normally sunny senator. He broke with precedent in testifying against a fellow senator, Jeff Sessions, during his confirmation hearings to be attorney general.

And he blasted Homeland Security Secretary Kirstjen Nielsen in January after she denied hearing Trump use vulgar words to denigrate African countries. "Your silence and your amnesia is complicity," he told Nielsen, recalling the "tears of rage" he shed when he learned of Trump's comments from news reports.

That remark prompted ridicule from conservatives but thrilled the left.

The Kavanaugh hearings may mark Booker's highest-profile confrontation with Trump to date.

"A lot of people think of him as being incredibly positive and uplifting, and may be surprised to learn that he also has this kind of tough, steady mettle internally," said Brigid Harrison, a professor of law and political science at Montclair State University.

Asked if his actions Tuesday betrayed his reputation, Booker said: "My record of working across the aisle is incredibly solid."

He and other Democrats argue the stakes are too high to go down quietly.

Still, the senator of uplifting quotes showed signs he's not entirely comfortable as an attack dog.

"I do hope you understand that I value your friendship," Booker said to Grassley, with whom he has worked on criminal justice reform. "I've come to have a deep respect for you, sir."

"If you worry about our friendship being affected," Grassley responded, "it will not be."