Joe Biden in Hampton, N.H., earlier this month. (Melina Mara/The Washington Post)

President Trump and his reelection campaign are opening up a fresh line of attack against Joe Biden, hitting the former vice president for his central role in a 1994 crime bill that has left Biden vulnerable to criticism from his right and his left.

As he prepared to leave Tokyo on Tuesday, Trump eviscerated Biden over his efforts behind the Bill Clinton-era law — one centerpiece of the tough-on-crime movement of the 1990s that Biden is being forced to confront on the campaign trail more than two decades later.

“Anyone associated with the 1994 Crime Bill will not have a chance of being elected. In particular, African Americans will not be able to vote for you,” Trump said in a pair of tweets going after Biden, whom the president repeatedly referenced during his four-day trip to Japan. “I, on the other hand, was responsible for Criminal Justice Reform, which had tremendous support, & helped fix the bad 1994 Bill!”

Using a derisive nickname he has created for Biden, Trump continued: “That was a dark period in American History, but has Sleepy Joe apologized? No!” 

Trump’s campaign manager, Brad Parscale, amplified that argument hours later Tuesday afternoon, ticking off several reasons the 1994 bill — officially called the Violent Crime Control and Law Enforcement Act — was a “TERRIBLE mistake,” including its disparities in sentencing guidelines for crack and powder cocaine offenses and its role in increasing incarceration rates. 

“It took President @realDonaldTrump to enact true Criminal Justice Reform!” Parscale tweeted. “Now the cycle is being broken.”

The latest volley from Trump toward Biden illustrates just how much criminal justice issues have scrambled political alliances on the campaign trail, with Trump signing a bill that was written by a potential 2020 rival (Sen. Cory Booker of New Jersey) while echoing Democratic candidates’ criticisms of one of Biden’s signature legislative achievements from his decades in office. 

Yet it also draws attention to Trump’s mixed history on criminal justice matters, including his focus on the Central Park Five, a group of black and Latino teenagers who were wrongfully imprisoned after a white female jogger was sexually assaulted in Central Park in 1989. At the time, Trump took out full-page ads in New York publications, calling for reinstatement of the death penalty following the incident, and Trump continued to insist that the Central Park Five were guilty — even though the five men were exonerated and another man confessed to the crime — as recently as 2016.

And Trump’s position on the 1994 crime bill has put him at odds with his personal attorney, Rudolph W. Giuliani, who was mayor of New York City when it recorded a steep decline in rates for murders and other violent crimes. 

“The 1994 Crime Bill passed by Pres. Clinton and Speaker Gingrich, with Biden & Schumer as the leaders in Senate and House, helped me and the NYPD reduce murder from @ 1,900 a year to @ 500 and then under Mayor Bloomberg to @ 350. That’s over 20,000 lives saved,” Giuliani tweeted on May 15, before Trump’s latest attacks on the law. Referring to Biden, Giuliani added: “Joe don’t cave.”

Trump and his supporters point to the enactment in December of the First Step Act, which made several significant revisions to mandatory minimum sentences for several drug offenses that were deemed disproportionately harsh by advocates of overhauling the prison system. 

The legislation, championed primarily by White House senior adviser and presidential son-in-law Jared Kushner, had been years in the making. It stalled during the Obama administration amid internal divisions among Senate Republicans, many of whom fretted that the bill would make them appear soft on crime. 

But Trump got behind the First Step Act, giving conservatives cover to back it. In addition to the sentencing-law revisions, the First Step Act also overhauled the prison system so certain nonviolent offenders can earn time credits if they participate in programs aimed at reducing recidivism. 

Since then, the White House has promoted the administration’s efforts to overhaul the nation’s prison system, inviting the first prisoner released under the new law as Trump’s guest to his State of the Union address in January and hosting a summit in April highlighting other beneficiaries of the law.

Considering that the campaign takes its cues from Trump himself, it is likely that his reelection apparatus will continue to hammer Biden over his role in the crime bill as long as Trump continues to fixate on it. 

“It is a known fact that the 1994 crime bill was terrible and led to unfair sentencing and the mass incarceration of black men. Even Bill Clinton says it was a mistake,” Erin Perrine, the campaign’s deputy communications director, said Tuesday. “So it isn’t a matter of how the campaign plans to use someone’s disastrous record. It’s a matter of, how does anyone with that record defend it?” 

The Biden campaign declined to comment on Trump’s remarks on Biden and the crime bill. The two camps engaged in a separate war of words Tuesday over Trump’s decision to approvingly cite a North Korean state-run media attack on Biden as a “low IQ individual,” with a Biden spokeswoman calling Trump’s attacks on the former vice president in Japan “beneath the dignity of the office.” 

Trump defended his remarks made abroad, tweeting after returning to Washington that he was “actually sticking up” for Biden. 

“I wish President Trump would focus more on the pressing regional situation with Kim Jong Un, the dictator of North Korea for whom he seems to have almost bottomless positive regard,” Sen. Christopher A. Coons (D-Del.) said in an interview Tuesday. But the Biden fixation, Coons added, showed that Trump “not only takes him seriously but considers him the strongest likely opponent.” 

Since officially entering the presidential race in April, Biden has talked sparingly about the 1994 legislation. In an appearance in Nashua, N.H., earlier this month, Biden insisted that the bill “did not generate mass incarceration” — although experts say it was one contributing factor and the law included incentives for states to build more prisons.

At that stop and during a National Action Network event in January, Biden did express regret over his support of some tough-on-crime provisions, such as the sentencing disparity between crack and powder cocaine offenses that both the Obama and Trump administrations later reduced. 

His allies say Biden has plenty to promote in his record when it comes to criminal justice efforts, including the federal assault-weapons ban that was included in the 1994 bill and the Violence Against Women Act. The Obama administration also commuted hundreds of sentences and pushed for other changes that reduced the federal prison population, Coons said.

“President Trump can cite one thing that he signed,” said Coons, one of Biden’s most prominent endorsers. “I think Joe Biden can cite a dozen things — legislation and policies — that as a senator and as vice president in the Obama-Biden administration he played a central role in getting advanced and signed into law.” 

Some of his Democratic rivals have sought to distinguish themselves from Biden’s criminal justice record. When asked about Biden’s assertion that the 1994 crime bill did not “generate” mass incarceration, Sen. Kamala D. Harris (D-Calif.) told reporters in Nashua last week that “I disagree, sadly.”

“I have a great deal of respect for Vice President Joe Biden, but I disagree with him,” Harris said. “That crime bill — that 1994 crime bill — it did contribute to mass incarceration in our country. It encouraged and was the first time that we had a federal three-strikes law. It funded the building of more prisons in the states.”

Candidates’ often-overlapping stances on criminal justice issues are a routine topic — and a frequent applause line — at town halls and rallies as the Democratic presidential contenders crisscross the country.

Sen. Bernie Sanders (I-Vt.) has talked about reducing the “disparity within the disparity” in the criminal justice system, where punishments disproportionately affect African Americans and minorities. He has also said felons should be able to vote from prison. Sanders also voted for the 1994 crime bill, saying on the Senate floor that he had “serious problems” with the bill but that it was urgently needed to decrease domestic violence. 

Sen. Elizabeth Warren (D-Mass.) has also talked about a criminal justice system “that has a problem of race right at the heart of it.” She speaks consistently on the campaign trail about getting rid of for-profit prisons.

Booker, who helped shepherd the First Step Act through the Senate, is now sponsoring the Next Step Act, which seeks to eliminate the crack and powder cocaine disparity. A Booker spokeswoman declined to comment on Trump’s tweet on his legislation or on Biden’s stance on criminal justice issues.

Harris argues that the nation should work to eradicate racial criminal justice disparities and reduce rates of mass incarceration. But the former prosecutor has been criticized for tough-on-crime policies such as a truancy law that jailed parents if their children skipped school. Sen. Kirsten Gillibrand (D-N.Y.) wants to create alternatives to prison for lower-level nonviolent crimes, and Beto O’Rourke has called for an end to the “failed war on drugs.” 

Felicia Sonmez and Chelsea Janes contributed to this report.