(Stock photo/ MorgueFile)

WASHINGTON – Sen. David Perdue is taking the kind of tough-on-crime stance that other Republicans usually applaud.

But attacking a bipartisan effort to reform prison sentences, which he derides as the “Criminal Leniency Act,” is drawing fire to the first-term senator from Georgia from other conservatives.

Perdue finds himself at odds with 16 Senate Republicans including Majority Whip John Cornyn, of Texas, and Chuck Grassley, of Iowa, chairman of the Senate Judiciary Committee.

The debate illustrates fault lines within the party over how far to go in changing mandatory prison terms.

Cornyn and Grassley are among those who say tough federal sentences are filling prisons with nonviolent criminals and costing taxpayers billions of dollars more to lock people up.

Perdue and others are reluctant to soften penalties lest violent criminals go free.

Perdue has pointed to the case of Wendell Callahan, a Columbus, Ohio man charged with stabbing his ex-girlfriend and her two young daughters to death in January. Callahan had been serving a 12-year drug trafficking charge but was released four years early, after mandatory sentencing guidelines for his crime were reduced.

“The idea that we are only allowing low-level criminals out of jail is a smoke screen,” Perdue said in a statement.

A provision barring violent criminals from having their sentences reduced leaves loopholes, he said, that “would put thousands of dangerous felons back on the streets early, potentially endangering our families and communities.”

Aides for Grassley and Cornyn – and advocates such as FreedomWorks, a conservative, pro-reform group – strongly dispute Perdue’s claims.

“In the wake of such a tragedy, it’s disappointing that some are attempting to play politics by using it to criticize efforts to improve the federal criminal justice system,” fired back Jason Pye, spokesman FreedomWorks.

Among the Senate Republicans supporting the bill are Kentucky’s Rand Paul and Missouri’s Roy Blunt. Pennsylvania’s Robert Casey and West Virginia’s Joe Manchin are among 19 Democrats backing the proposal.

Reforming mandatory sentencing laws has been an emphasis for Democrats who’ve been concerned with racial disparities from stiff drug laws passed in the 1990s. Republicans seeing an opportunity to cut spending have driven the recent push for reform.

Tough sentences are costly because they fill prisons with mostly non-violent drug offenders, argue conservative supporters of reform including Charles G. Koch, a top Republican donor and Koch Industries chairman, who made the case in an op-ed for Politico last year.

A number of states under Republican leadership, including Texas and Georgia, have revised sentencing guidelines in response to overcrowded prisons.

Texas’ reforms allowed the state to escape $3 billion in prison construction costs, while reducing recidivism and crime, Pye said.

The proposal in Congress, sponsored by Grassley, would reduce sentences including the life-in-bars punishment now given to three-time drug offenders, dropping it to 25 years. It reduces a number of minimum sentences for other drug crimes, giving judges more discretion to dole out punishment.

At the same time, the proposal applies minimum sentences to some violent felonies, now only applied to drug crimes. It creates a new sentence for drug crimes involving fentanyl, the opioid blamed in a rash of overdose deaths. It also emphasizes creating rehabilitation programs.

Grassley said in a statement the bill, which is similar to a proposal in the House, balances tough punishment for major criminals with the need to clear prisons of “low-level, nonviolent offenders.”

Reform supporters have made a number of changes from their original proposal last year.

The latest version, unveiled last week to sway holdouts, explicitly excludes those convicted of serious violent felonies – including crimes in which firearms are used – from being eligible for reduced sentences.

That was good enough for the National District Attorneys Association, which also had been concerned that the original proposal could have let some violent criminals out early.

Other Republican senators – including Perdue’s seatmate, Johnny Isakson, and Pennsylvania’s Pat Toomey – are still on the fence.

Perdue, though, argues that criminals like Callahan would still be eligible for reduced sentences on drug charges.

Grassley and Cornyn aides note Callahan was previously convicted of a non-fatal shooting, considered a violent felony, which would have made him ineligible for a reduced sentence under the proposal.

Perdue disputes that the earlier charge would be considered a serious, violent felony in the bill.

In a letter sent to senators before the bill’s latest revision, Perdue and three colleagues, including Alabama’s Jeff Sessions, described the “heinous murders” in Ohio as a cautionary tale of the consequences of releasing “thousands of violent criminals.”

The proposal, the wrote, is a “risky and possibly devastating social experiment in criminal leniency.”

Kery Murakami is the Washington, D.C. reporter for CNHI’s newspapers and websites. Reach him at kmurakami@cnhi.com.