We are expected to believe that in 2016 many California districts had a 70-80% turnout - for Hillary Clinton?
http://vote.sos.ca.gov/returns/status/
when the average turnout rate for obama in 2012 was 55%?
http://www.electproject.org/2012g
Those are not apples to apples comparisons - the first is % of registered voters. The second is % of voting eligible adults, regardless of registration status.
That said, the # of presidential votes went up in 2016 by 6.5% vs 2012 while the population growth was up around 4.0% (including illegals).