One reason for bipartisanship is that the criminal justice system has affected so many people — 30 percent of American adults have a criminal record, which the F.B.I. defines as an arrest on a felony charge. “Every single American family is impacted by the broken justice system,” said Holly Harris, the executive director of Justice Action Network, which works with Republicans and Democrats at the federal and state level to reform criminal justice.

This is in large part because substance abuse now affects everyone. The crack cocaine epidemic of the 1980s and 1990s fueled mass incarceration because many white people (who made the laws) saw addicts — largely African-Americans from city neighborhoods — as criminals to be feared. Not any more. “It’s crawling across everybody’s back yard,” Ms. Harris said.

This is what sets criminal justice apart. We can’t demonize the other side, because they are us. Yes, the race and class disparities are still horrendous. But we probably wouldn’t have the First Step Act today had Jared Kushner’s father not served 14 months in federal prison beginning in 2005 for tax evasion, witness tampering and making illegal campaign donations.

The Justice Action Network is the advocacy arm of the Coalition for Public Safety, which began in 2015 to gather organizations like the American Civil Liberties Union and the N.A.A.C.P. on the left, and Right on Crime and Faith and Freedom, on the right.

This is unusual. “Lots of groups are nonpartisan, but that’s not the same as ensuring weight for progressives and conservatives,” said Inimai Chettiar, the legislative and policy director for the Network and the Coalition, both of which are primarily funded by Laura and John Arnold.

The Network forms similar bipartisan coalitions in states, and works with legislators such as Mr. Harris and Ms. Delozier. It began in Pennsylvania, Ohio and Michigan, and next year will work in 20 states. At the federal level, the Network’s advocacy was crucial to expanding the First Step Act to include sentencing reform.

The Network will only pursue a reform if its motley group of members unanimously agree. Those issues don’t include policing, guns or the death penalty — issues on which partisan divides are strong. The Network does work on reforming pretrial detention, sentencing, probation and parole, civil asset forfeiture laws, and the fines and fees charged to defendants and inmates. It also works to establish alternatives to incarceration, more humane treatment for women in prison, and a path after prison to a successful, law-abiding life.