When California’s independent redistricting commissions drew new maps of the state’s congressional and legislative districts after the 2010 and 2020 censuses, their members were emphatically told by legal advisors that the federal Voting Rights Act required them to maximize opportunities for ethnic communities to elect officeholders.

The commissions went to great lengths to fold that mandate into the geographic boundaries of the districts, even if it required them to ignore city and county lines.

The effect was to enhance the ranks of Black, Latino and Asian representatives in Congress and the state Capitol. It also helped Democrats achieve overwhelming majorities in the Legislature and the state’s congressional delegation, thus leaving Republicans with only token representation.

The commission’s redistricting plans were, in effect, gerrymanders, if one defines that term as meaning to seek predetermined outcomes — even though the commission was created, via two ballot measures in 2008 and 2010, in response to gerrymanders the Legislature had decreed in prior decades.

Last year, Gov. Gavin Newsom and the Legislature asked voters to set aside the commission’s overwhelmingly pro-Democrat congressional districts and adopt even more lopsided maps, to give Democrats five more seats. It was a response to efforts, backed by President Donald Trump, to gerrymander more Republican districts in Texas and other red states.

Voters agreed by passing Proposition 50. This year’s election will test whether the gerrymander has been successful and whether it has enough impact to restore Democratic control of the House of Representatives.

While setting aside the redistricting commission’s maps, Prop. 50 promised that the maps would be effective not only this year, but for the 2028 and 2030 election cycles, after which the commission process would be restored using data from the 2030 census.

It’s difficult to believe that when the time comes Democrats would truly allow the commission to once again draw the maps. The party’s leaders never liked the commission process in the first place, and returning to it could force them to give up some of the seats they are capturing this year.

Additionally, California’s congressional delegation, now 52 members, is likely to shrink by four or five seats due to the state’s lack of population growth, meaning even fewer positions to distribute.

On Wednesday, the U.S. Supreme Court gave California’s Democratic Party leadership another reason to eliminate the redistricting commission by weakening the Voting Rights Act’s effect on drawing districts to maximize representation by non-white ethnic groups.

By a 6-3 vote, the court overturned congressional maps in Louisiana that had, by lower court order, been redrawn to create one more district for the state’s Black residents. The split decision declared that a “racial gerrymander” violates the U.S. Constitution’s equal rights language.

The revised congressional districts that California created via ballot measure last year will not be immediately affected by Wednesday’s ruling, but it could impact states that had been weighing making changes but had not yet done so.

Furthermore, it could affect California’s new maps going forward. When they were placed on the ballot, Democratic leaders boasted that they were fully in compliance with the Voting Rights Act’s provisions that now have been reinterpreted. Republicans could contend via lawsuit that the maps are unconstitutional under the court’s new standard.

The Supreme Court’s ruling would also affect how California’s redistricting commission approaches its task after the 2030 census by eliminating, or at least weakening, the mandate that guided its actions in the past.

Democratic leaders could minimize the court’s decree by persuading voters to eliminate the commission, thus returning redistricting to a Legislature they overwhelmingly control —something they probably would prefer anyway.

Dan Walters is one of most decorated and widely syndicated columnists in California history, authoring a column four times a week that offers his view and analysis of the state’s political, economic,...