Bernie Sanders supporters who complain that the Democratic primary contest is rigged may have an ironic point. Look how he was denied what might have been a bigger victory in California on Super Tuesday that would have countered Joe Biden’s Eastern U.S. rout narrative. Blame incompetent progressive government.

California’s tally at our deadline Friday had Mr. Sanders with 33.6% of the statewide vote to Mr. Biden’s 25.3%. But about three million mail-in and provisional ballots still have to be counted, and the state has until...