In a new column published today in Rolling Stone, Iowa senator Chuck Grassley stated, when asked how he came around to advocating reform to the federal prison system, that positive experiences from the states were a contributing factor:

“I’ve learned from what some states have done, changes could be made and money could be saved and not hurt society with people that do harm coming from behind bars.”

This is an important point, and one that should probably figure the heaviest as federal lawmakers consider the Sentencing Reform and Corrections Act—recently passed out of the Senate Judiciary Committee by a 15-5 vote—or other similar legislation.

For the last decade, conservative states such as Texas, South Carolina, Georgia, and others have taken the lead in implementing data-driven, empirically-based criminal justice reforms that have reduced corrections costs, provided for diversionary programs—e.g. drug courts, increased use of probation, etc.—in lieu of incarceration that can yield better outcomes, and most importantly, improved public safety.

For instance, since Texas started passing its largest reforms in 2007, the state has closed three adult prisons—and several more juvenile facilities—with total corrections savings of around $3 billion. Recidivism is down, and crime has fallen to its lowest level since the late 1960’s—at the same time, it should be noted, as maintaining mandatory sentences for only violent or repeat offenders. As a result of this, the incarceration rate also shrunk by about 12% between 2009 and 2014.

In fact, between those years, more states (thirty) that reduced their incarceration rates experienced the largest concomitant reduction in their crime rates than did those states that imprisoned more people (nineteen), according to the Pew Trusts. This runs directly counter to the suggestion of federal prison reform critics that lowering incarceration through reduced mandatory sentences/retroactivity will be detrimental to public safety per se. The relationship between incarceration and crime rates is complex—if a meaningful one even exists. However, experience has shown that lowering both at the same time is possible.

It’s long been understood in American jurisprudence, both in theory and practice, that justice is best administered at the state level. In this way, states have the latitude to respond to their own unique circumstances, innovate the best modalities for addressing them, and allow other states to adopt them where appropriate. To the extent that federal government has a role to play with its own justice system, the states have demonstrated what works, and federal lawmakers drafting new legislation are wise to make these lessons the basis of their own efforts.

It’s heartening to see Sen. Grassley and others recognize this.