A head to head comparison of the California 2016 General Election gives us an idea of the break down of the voters.    

Hillary Clinton received 8,753,788 votes beating Donald Trump who gained 4,483,810 by a massive 4,269,978 votes in  California.                                        

Hillary Clinton won 33 counties out of the 58 counties that make up California. The record shows that Donald Trump won 25 counties.  

2016 CA  Primary Election vs Presidential General Elections Counties Won              

Primary Elections

Presidential General Election

             

Primary Election

In the Primary, Sanders won the 7 counties in a 3 way match up. However, on a head to head match up between Hillary Clinton and Donald Trump, she won 26. She no doubt kept and Bernie's 7 counties that he won over Trump, went for Clinton in the general elections.    

2016 CA Presidential Primary vs Presidential General Elections w.r.t % Votes and Total Votes Won        

Primary Election

Presidential Election

On a head to head count with the total votes between in Hillary Clinton and Donald Trump between the primary and general, % vote shift difference is 4% decrease for Donald Trump and a 4% increase for Hillary Clinton. These percentages are represented by a vote increment of 6,040,529 for Clinton and 2,848,461 for Trump at the Presidential General Elections. There is a whooping 6,040,529 Vote difference between Clinton and Trump.

Presidential Primary Elections

Presidential General Elections

During the 2016 General elections, over 146,434,269 total number of votes were cast.  Hillary Clinton got 65,849,971 (65.8 Million) over Donald Trump's 62,984,405 (62.9 Million). She won the popular vote by 2,865,566 (2.8 Million).  Her win in the State of California was as a result of a 3,369,978 vote margin. This represents 11.7% of her popular vote victory. The remaining 49 states contributed to her the remaining 88.3 popular votes victory.

Top 15 Counties in Primary Elections vs General Elections

All Candidates (Primary Elections)

All Candidates (General Elections)

Primary vs General

These 15 counties play an important role in these primary elections. If a candidate, can get a sizable majority(like Hillary Clinton) in the biggest county (Los Angeles - 3 times the size of the second biggest county by vote count), it becomes very difficult to win majorities in the smaller counties with out voter out reach and increased voter participation in them.

Top 15 Counties Comparison in Primary Elections vs General Elections

Primary Elections
Hillary Clinton

Primary Elections
Donald Trump

General Elections
Hillary Clinton

General Elections
Donald Trump

Los Angeles which is the biggest county by far voted 3:1 ratio for Hillary Clinton giving her a 1.7 Million vote advantage out of that county. The next 9 top counties that voted in favour of Clinton gave a vote advantage of between 50,000 to 400,00. This made it hard for Donald Trump to catch up or reduce the vote count difference. Where ever Donald Trump won, his margins of victories were never in the Million range or hundreds of thousands  but only tens of thousands, making Hillary Clinton gain an upper hand in the State of California.

Related References: 2016 California Primary Election Story, 2020 California Primary Election Story