California is once again a hot spot in the battle over the rising cost of health insurance.

The issue has attracted national attention, and Health and Human Services Secretary Kathleen Sebelius has pledged to "stand ready to assist [Mr. Jones] and the people of California in any way that we can."

California was a focal point of debate over insurance premiums last year, too, when Mr. Jones's predecessor drew attention to a 39% increase by WellPoint. Errors were uncovered in the rate filing, and WellPoint reduced its increase to an average of 14%. Mr. Jones, then chairman of the state Assembly's health committee, asked a WellPoint executive in a hearing, "Have you no shame?"

"We have a long history in California of 10%, 20%, 30%, 40% rate hikes," said Mr. Jones, a Democrat, in an interview. "This is just business as usual."