California voters have upheld the state Senate districts drawn last year by an independent citizens' commission.
A majority voted "yes" on Proposition 40 on Tuesday after the original challengers dropped their opposition to the new political boundaries.
Republican-backed officials had sought the referendum because they feared the new Senate map would hurt their candidates' chances. They did not challenge the newly drawn Assembly districts.
The GOP stopped actively campaigning in July after their legal challenges to the maps failed in state and federal court. But by then the measure had already qualified for the ballot.
Had voters rejected the maps, the ballot measure would have required court-appointed officials to set interim boundaries for the 40 state Senate districts until new maps could be drawn.