For the past six months, the president’s son-in-law Jared Kushner has been working on a potentially bipartisan initiative: to reform the U.S. criminal justice system.

Kushner has been holding “listening sessions” to develop White House agenda on criminal justice reform, including policy recommendations such as providing incentives to companies for hiring former felons, investing in inmates once they leave prison, and perhaps most importantly, reforming sentencing laws, including mandatory minimum sentencing, a relic of the 1980s and 90s war on drugs and the focus of a three-year bipartisan reform effort in the Senate.

It all culminated in last week’s White House roundtable discussion on prison reform with President Trump, several Republican governors, and conservative activists. Except one thing was missing: sentencing reform. Attorney General Jeff Sessions opposes reforming mandatory minimum sentencing and effectively blocked it from becoming part of the White House reform agenda, according to three people who attended meetings with White House advisors on the issue over the past few months.

“Sessions was very powerful in the Senate, but I think he’s actually more powerful now to oppose the bill,” a source familiar with White House meetings on the issue said. “He has an ability to keep in line several members on the conservative side, the DOJ would take a position on the bill, that would scare the Republicans.”

As the prison reform debate played out, Kushner expressed support for limiting mandatory minimum sentencing, according to individuals who have discussed these issues with him, aligning him with Senate Republicans on the Judiciary Committee. But Kushner dropped the issue from the agenda in order to get Sessions to attend the roundtable discussion last week.

At the meeting Trump suggested creating more programs for job training, education, mentoring and drug addiction aimed at rehabilitation. There was no discussion of sentencing laws. The White House did not respond to a request for clarification about the Kushner’s nor the White House’s official position on sentencing reform.

“The president directed the Attorney General to reduce violent crime in this country and he is focusing the Department’s efforts on achieving that goal. Incarceration remains necessary to improve public safety, and the effectiveness of incarceration can be enhanced by the implementation of evidence-based reentry programs,” a spokesperson for the Department of Justice said.

“They were never going to be able to get the President to say he supports sentencing reform based on what Sessions has told him,” a source familiar with the meetings said.

Read more: Prisons are still charging female inmates for having their period

A majority of Republicans and Democrats support reforming mandatory minimum sentencing, which takes sentencing leeway away from judges. Since then the federal prison population has quadrupled; more than half of all federal inmates were sentenced using mandatory minimum laws.

Meaningful sentencing reform is considered key to any reform package that could be brought to vote in the Senate. Republican Sen. Chuck Grassley of Iowa, Judiciary Committee Chairman, said sentencing reform is a must-have if Trump wants a bill to pass.

“Any proposal that doesn't include sentencing reform is not going to get through the committee,” a spokesman for Grassley said in an email.

Last week’s roundtable discussion included Kushner, who’s father spent time in federal prison for illegal campaign contributions and tax evasion, Sessions, Republican governors Matt Bevin of Kentucky, Sam Brownback of Kansas, and Nathan Deal of Georgia, as well as representatives from conservative organizations.

In October, the Senate Judiciary Committee unveiled its latest criminal justice reform bill — the Sentencing Reform and Corrections Act — to eliminate many mandatory-minimum sentences for drug crimes. This is not the first time Congress has tried to pass comprehensive reform. The same bill made it out of the committee in 2015, but was never voted on due to loud opposition from a group of Republicans, including then-Senator Jeff Sessions.

Sentencing reform has the support of some Republican governors who feel that they contribute to mass incarceration, a drain on local economies. Holly Harris, former general counsel for the Republican party in Kentucky who has attended talks with Kushner over the past several months, said Republicans should consider the midterm elections when they decide where they fall on criminal justice reform.

“Across the board in a dozen states including Rust Belt battle states, women overwhelmingly support criminal justice reform, including reforming mandatory-minimum sentences,” she said. “Those who don’t pay attention to what voters want in their own backyard do so at their political peril.”

Other critics the White House agenda contrasts sharply with policies the Trump administration has been pursuing. For example: the Federal Bureau of Prisons ended contracts with 16 transitional housing facilities in October, slashing the number of available beds available for ex-felons looking to reintegrate into society.

Pat Nolan, the director of the Center for Criminal Justice Reform at the American Conservative Union Foundation hopes that Congress will reverse the cut.