“We have in the past and will in the future have criticism of the policy agenda of the Koch brother companies, but where we can find common ground on issues, we will go forward,” said Neera Tanden, the president of the center. “I think it speaks to the importance of the issue.”

Image Mark Holden of Koch Industries said that it was willing to collaborate. Credit... A.J. Chavar/The New York Times

With the huge costs to the public of an expanding 2.2 million-person prison population drawing interest from the right and the conviction that the system is unfair and incarcerating too many drug and nonviolent offenders driving those on the left, the new coalition is the most recent example of ideological opposites joining together.

Last year, Senators Cory Booker, Democrat of New Jersey, and Rand Paul, Republican of Kentucky, together wrote legislation aimed at helping nonviolent offenders seal their records. This month, Senator John Cornyn of Texas, the No. 2 Republican in the Senate, and Senator Sheldon Whitehouse, Democrat of Rhode Island, introduced legislation aimed at cutting prison populations by allowing eligible prisoners to reduce their time.

The coalition’s goal is to leverage the broad reach of the group’s partners and financial backers to build public support for overhaul efforts through research and education campaigns, among other initiatives. The ideological spread should also allow them to reach out credibly to lawmakers of both parties.

“These groups bring an opportunity to really reach a broader audience,” said Christine Leonard, a former congressional and White House aide involved in criminal justice issues, who will direct the coalition.

The idea for the group grew out of a meeting in Washington on Oct. 15 at the impetus of the Arnold Foundation. About three dozen activists along the ideological spectrum met in a conference room at the Pew Foundation — a process Mr. Calabrese described as “putting dogs and cats together in the same room.”

He said those at the all-day meeting were challenged to find a way to collaborate on criminal justice given their shared sentiment that the system was not working and was exacting a steep toll in public dollars and also in damaged lives and significant losses to the economy.