WASHINGTON — For Cory Booker, the Senate’s approval of a landmark criminal justice reform bill Tuesday night is perhaps his most significant policy achievement in Washington — and a well-timed one.

The vote comes as Booker nears a decision on whether he will run for president in 2020, and after the New Jersey Democrat has made criminal justice reform one of the central causes of his time in Congress.

If he chooses to run, as is expected, Booker could point to momentum on an issue that has become a priority for many liberal voters, and is one with broad appeal. Along with being one of the effort’s most visible supporters, Booker pushed to ensure that the final bill included a virtual ban on solitary confinement for juveniles in federal prisons.

“Our criminal justice system, as it stands right now, is an affront to who we say we are as a nation,” Booker said on the Senate floor Tuesday. “We profess, we actually swear an oath to the flag, that we are a nation of liberty and justice for all, but our criminal justice system violates those values.”

The measure, which has received a big push from President Trump, passed the Senate easily, with dozens of Republicans joining every Democrat. It must clear the House, which approved a less ambitious set of reforms earlier this year. That chamber is expected to act this week.

The policy victory could help answer a criticism that has shadowed Booker: He is great at the showy sides of politics, but less devoted to the nuts-and-bolts work.

When Senate Minority Leader Chuck Schumer (D., N.Y.) praised individual senators for their work on the bill Tuesday, Booker was the second person he named, after the Senate’s second-ranking Democrat, Sen. Dick Durbin (D., Ill.).

Schumer said Booker “knew when to hold, knew when to fold," in accepting an agreement to support the bill.

The effort’s bipartisan nature could also help a potential presidential candidate. Booker was among the Democrats who worked closely with conservative Republican senators such as Utah’s Mike Lee and Iowa’s Charles Grassley to pull the bill together.

The measure would be one of the most significant federal sentencing reforms in years and one of the only major policy measures to pass in this Congress with wide bipartisan support. It drew an unusual coalition. Democrats and civil rights activists focused on reversing consequences of tough-on-crime laws that they say led to too much incarceration, lengthy sentences out of step with the crimes committed, and tougher treatment for minorities and poor people.

Conservatives and libertarians, including the political network founded by the mega-donor Koch brothers, saw heavy incarceration rates as a waste of money and lives, arguing that people who had served their time should have a chance to contribute to society.

As Booker noted, a Congressional Research Service report found the federal prison population has increased nearly 800 percent since 1980.

The plan would reduce some mandatory-minimum sentences for drug crimes, including the three-strikes law requiring life sentences, and offer judges more discretion in sentencing for low-level offenses. It also includes more opportunities for inmates to shorten their sentences by taking part in rehabilitation programs and bars certain practices, including shackling pregnant prisoners.

Booker predicted that the bill will affect “thousands” suffering from injustice.

Conservative critics, however, warned that it could lead to the early release of violent criminals.

“A number of serious felonies, including violent crimes, are still eligible for early release,” Sen. Tom Cotton (R., Ark.) wrote in the National Review. “In short, the First Step Act flunks their basic test to protect public safety.”

Ironically, Booker reached this long-held goal with an assist from the president he may try to replace. Trump supported the measure and cajoled Senate Majority Leader Mitch McConnell (R., Ky.) to allow a vote. It is the first significant bipartisan policy achievement of the Trump presidency.

“This will keep our communities safer, and provide hope and a second chance, to those who earn it. In addition to everything else, billions of dollars will be saved. I look forward to signing this into law!” Trump tweeted Tuesday night.

Every senator from Pennsylvania, New Jersey and Delaware supported the bill, including Pennsylvania’s Pat Toomey, its lone Republican senator.

Booker took up sentencing reform almost as soon as he arrived in the Senate. He teamed up with Sen. Rand Paul (R., Ky.) to introduce an early proposal, and was later a key figure in a bipartisan deal unveiled in 2016, a precursor to the measure passed Tuesday.

Schumer said then that Booker was “the conscience” of the effort.

On the Senate floor, Booker, of Newark, spoke in personal terms, saying he is the only senator living in a mostly minority neighborhood.

“I still live in a community that is both over-criminalized and under-protected because of federal policies … that mistake the severity of a punishment with the actual security of a people,” he said.

Booker toured all 21 New Jersey counties to promote the issue and made countless television appearances and speeches. On a Utah radio station with Lee, he talked up the messages of forgiveness found in the Bible. In 2017 he hosted Eagles safety Malcolm Jenkins and other current and former NFL players as they visited Capitol Hill to argue for criminal justice reforms and improved relations between police and minority communities.

Booker has said he will make a decision on the presidential race over the holidays; he is widely expected to announce his intentions early next year. Recent visits to Iowa and New Hampshire, the first two states with nominating contests, have only accelerated speculation.

Booker, in an interview last week, said he plans to keep the criminal justice issue in the spotlight. He called this bill “a first step” and lamented that some provisions he sought were left out.

“As soon as the ink is dry on this, I’m going to take a holiday vacation and come back to work on criminal justice reform,” he said.