The issue focused on House legislation that would prohibit federal money from being used to impose federal laws on medical marijuana in states where it is legal. House Republicans say that federal law already prohibits federal money from being used to penalize states that legalize medical marijuana.

But federal law gives the Justice Department wide latitude to decide how to enforce federal law. For example, the Justice Department has already begun criminal prosecutions of medical marijuana providers in California.

In court papers, the Justice Department says that federal law gives federal law