In 2003, voters decided to remove Gov. Gray Davis, a Democrat, from office and replace him with Republican Arnold Schwarzenegger.
Back then the state was more of a "purple" mix of voters - favoring Democrats but still with a substantial Republican population, experts say. Today it's much more solidly in the Democrat corner.
Additionally, the state has added more Latino and Asian-American voters, and they tend to vote Democrat more often, although their turnout figures lag other groups, experts say.
For a deeper look at how California's demographic mix is likely to impact Tuesday's recall, please watch the video above.