The battle lines are being drawn in a bitter feud between centrist Democrats and progressives in California over changes to Proposition 47, a decade-old law blamed for the rise in drugs and theft in the state.

California voters will decide in November on Proposition 36, a measure that will determine how the state should punish people who have repeatedly been convicted of stealing or committed crimes involving fentanyl, a deadly synthetic opioid up to 100 times more potent than morphine.