The “50%+1” rule was just a typical election loophole known to every political insider, to the detriment of voters.
But, with the success of Measure K and companion Measure L, now prevent the City of San Diego from electing candidates and passing initiatives in low-turnout primaries.
That success then expanded to the County of San Diego where the voters passed Measure D just two years later. This eliminated the "50%+1" loophole for the entire county.
Most voters assume that the important stage of the election is the general election. That is why turnout is often DOUBLE that of a primary.
Before Measures K&L, a loophole allowed elections to end at this early stage.
What Measures D, K & L did was eliminate the confusion, close the loophole, and ensure that important decisions are made when the most people participate.