CHICAGO (CBS) — A rare example of bi-partisan cooperation led to a major victory for Mayor Rahm Emanuel.

Superintendent Eddie Johnson testified before an Illinois House committee at 11 a.m. Thursday to support legislation aimed at cracking down on gun violence in Chicago.

The committee approved stiffer sentences for repeat gun offenders, something Mayor Emanuel has demanded for years.

The superintendent testified on the legislation in March, when it came before an Illinois Senate committee.

Johnson said, all too often, violent criminals in Chicago are given a slap on the wrist for gun violations, when they should be locked up for a long time.

“It’s the repeat offenders who repeatedly come back into our neighborhoods to shoot and kill. And if we don’t send them a message about holding them accountable, then what are we doing?” Johnson said.

Under current state law, offenders charged with unlawful use or possession of a weapon by a felon face 3 to 14 years in prison. State Sen. Antonio Munoz and Sen. Kwame Raoul have proposed legislation that would recommend repeat offenders get 7 to 14 years instead.

If a judge gives less time, he will have to explain why, in writing. But also built in is a diversion program for non-violent first-time gun offenders under the age of 21.

“I lent myself to this negotiation and this process because of the violence that was happening outside my home,” said. Sen. Kwame Raoul.

In March, Johnson said police need the tougher punishments to help them stop violent crime in Chicago.

“If an individual shows a repeated willingness to pick up a gun and use it illegally, those individuals need to pay a price,” he said.

The superintendent said about 1,500 people in Chicago are responsible for most of the violent crime, and the proposed legislation would target that group.

Mayor Rahm Emanuel said, without the tougher sentences, the Illinois criminal justice system will continue to have a “revolving door” for habitual gun offenders.

“I support absolute tough, certain sentencing for repeat gun offenders,” he said. “I don’t understand what it takes. The repeat part is your first signal they don’t belong on the streets terrorizing kids and families.”

The strongest opposition came from black legislators and progressives who believe longer jail terms do not work.

“I can’t in good conscience support legislation where there is not research to support this id going to be the thing to help us,” said Illinois Representative, Juliana Stratton.

“It does not address the root causes of crime. It does not prevent crime. It simple puts more people behind bars,” said Illinois Representative, Will Guzzardi.

But the measure passed out of committee, 10 to three. And now moves to the full House ruled by Speaker Mike Madigan.

“Hes supportive of it and he’s very optimistic that we can get it across,” Johnson said.

A proposed House amendment to the legislation would create a pilot program for non-violent offenders charged with gun crimes. The program would focus on rehabilitating first-time offenders and keeping them out of prison.

It’s also meant to ease concerns of some inner-city lawmakers who have said the legislation utterly fails to crack down on gun dealers and suppliers.

The measure is something of an experiment, expiring in five years and renewable if it is effective. Superintendent Eddie Johnson predicted it could cut Chicago gun violence by as much as 50 percent, with results showing up within a year.

The Senate approved the legislation by a 35-9 vote in April.

If the measure passed the full House, the Senate would have to sign off on those changes before the legislation could go to the governor’s desk. The word from minority leader Jim Durkin is, Governor Rauner will sign it.