Our country's federal prison population has grown by nearly 800% in the last 30 years.

Seriously. That's not a typo. Fueled by the failed "War on Drugs" and extreme, one-size-fits-all sentencing, our federal prison population has ballooned out of control. And unless we do something about it, it's going to keep growing and growing for decades to come.

The Senate Judiciary Committee took one big step forward toward a fairer and more humane criminal justice system last week by passing the Smarter Sentencing Act, introduced earlier this year by Sen. Dick Durbin (D-Ill.), Sen. Mike Lee (R-Utah) and Sen. Patrick Leahy (D-Vt.).

Unfortunately, the Committee also voted to add three new mandatory minimum sentences for domestic violence, sexual assault and terrorism crimes. The American Civil Liberties Union supports the Smarter Sentencing Act, but we don't support the new mandatory minimums. The bill now moves to the Senate floor for consideration.

The Smarter Sentencing Act is the most significant piece of criminal justice reform legislation to make it to the Senate floor in several years. This bill would make progress toward fixing our broken criminal justice system primarily by reducing mandatory minimum sentences for certain drug offenses. Research by the Urban Institute found that increases in expected time served, like those shortened by the Smarter Sentencing Act, contributed to half of the prison population growth between 1998 and 2010. The bill also gives judges more leeway when sentencing people who do not pose a public safety risk and applies the Fair Sentencing Act—which reduced the crack-powder cocaine sentencing disparity —to those currently serving sentences for these offenses.

Extreme, one-size-fits-all sentencing has caused our federal prison population to balloon out of control, and it's time to change these laws that destroy lives and waste taxpayer dollars. If passed, the Smarter Sentencing Act would save thousands and thousands of people from unnecessarily harsh prison sentences and put a couple extra billion dollars in America's pocket. By significantly shortening many federal prison terms, the Smarter Sentencing Act would save taxpayers billions of dollars. It costs about $29,000 a year to house just one federal inmate, and with almost 216,000 people in federal custody , that's a lot of savings to put toward reducing the federal deficit.

The ACLU is disappointed by the new mandatory minimums added in committee, but the Smarter Sentencing Act is a much needed next step toward a fairer criminal justice system. There are many good reasons to support this bill, and we are encouraged that the legislation passed out of committee with bipartisan support. It's a shame that by including the new mandatory sentences, members of the Committee are ignoring recent research that finds mandatory minimum sentences are a major reason for our out of control prison population.

We cannot overlook the fact that more than 60 percent of federal district court judges agree that existing mandatory minimums for all offenses are too high, and Attorney General Eric Holder has called our current state of widespread incarceration "both ineffective and unsustainable ."

Could 2014 be the year we finally curtail our country's extreme sentencing laws that destroy lives and waste taxpayer dollars once and for all? Only time will tell, but we hope the Senate takes this opportunity to make smart reforms and passes the Smarter Sentencing Act.