WASHINGTON — An unusual alliance of Tea Party enthusiasts and liberal leaders in Congress is pursuing major changes in the country’s mandatory sentencing laws.
What’s motivating them are growing concerns about both the fairness of the sentences and the expense of running federal prisons.
The congressional push comes as President Obama and his Cabinet draw attention to the issue of mandatory sentences, particularly for nonviolent drug offenders.
Supporters say mandatory minimum sentences are outdated, lump all offenders into one category, and rob judges of the ability to use their own discretion.
They also cite the high costs of the policies. The Justice Department spends some $6.4 billion, about one-quarter of its budget, on prisons each year, and that number is growing steadily.
‘‘People are coming here for different reasons, but there is a real opportunity,’’ said Senator Dick Durbin, Democrat of Illinois, one of the Senate’s leading proponents of sentencing changes.
The push is being led by the Senate, where Durbin has worked with Tea Party stalwarts such as Senator Mike Lee, Republican of Utah, on legislation that would give judges more flexibility to determine sentences in many drug cases. At the same time, a right-left coalition is pressing for changes in the House.
Tough-on-crime drug policies once united Republicans and Democrats who didn’t want to appear weak on crime. Now reversing or revising many of those policies is having the same effect.
The Fair Sentencing Act, passed in 2010, drew bipartisan support for cutting penalties on crack cocaine offenses. The bill reduced a disparity between crack-related sentences and sentences for other drugs, though it only addressed new cases, not old ones.
Durbin, one of that bill’s chief sponsors, has written a much broader bill with Lee, called the Smarter Sentencing Act.
It would expand a provision that gives judges discretion for a limited number of nonviolent drug offenders. The new law would allow judges the same latitude for a larger group of drug offenders facing mandatory sentences.
It’s one of four bills dealing with sentencing that the Senate Judiciary Committee is expected to take up early in the year. The committee chairman, Senator Patrick Leahy, Democrat of Vermont, said he wants one consensus bill to clear the committee.