California Dems ask Justice to investigate JPMorgan energy trades

Now, congressional Democrats want to see the Justice Department get involved, arguing the bank's actions are harming Californians and making it harder for the state to balance its budget.

"To ensure that California's energy markets are free of fraud and abuse, and that no individual or company is above the law, we urge you to conduct a thorough investigation into whether our energy prices have been manipulated," they wrote.

Rep. Dan Kildee (D-Mich.) made a similar request of Holder in May, after reports indicated similar manipulation may have occurred in Michigan.

"The people of Michigan, and the American public generally, deserve a marketplace where all participants play by the same rules. I urge the Justice Department to resolve this matter by investigating these potentially illegal practices," he wrote, according to Reuters.