State governments have long lured workers with the promise of lucrative pensions that provide nearly the pay in retirement that employees earned on the job. But after years of budget crunches, nearly every state has revamped public retirement benefits in an effort to shrink the long-term obligations that are billions of dollars short of what is needed to cover benefits.

The moves have triggered a legal and political battle over whether states are reneging on their promises to millions of public-sector workers.

Governors from Louisiana Republican Bobby Jindal to California Democrat Jerry Brown face intense opposition from labor groups, workers and even traditional political allies as they try to change pension rules. And some battles have shifted to the courts.