News accounts have focused on this chart in Gov. Brown's recent budget proposal which shows the Latino/Hispanic state population exceeding the white-Anglo population by July. That the shift would occur sometime this decade was obvious from the 2010 Census. A news account indicates that the shift will occur in March. Clearly, putting an exact date on the shift is not really possible. But the change will definitely have occurred by the next Census. (Official state estimates for the California population at the time of the 2010 Census were way off. So interim estimates between Census years always have a significant chance of error.)
In terms of voting, the Latino/Hispanic share of likely voters was about half their share of the population in 2010 due to citizenship and voting propensities. But that, too, is changing.