I would have to highly and strongly disagree with @TheDidactic statement of “leadership is an overrated non-essential.” Leadership, ESPECIALLY in the UC system, is so important. It is truly a holistic review and I am a perfect example of that. A friend of mine works at a UC admissions office and I got help from him, knowing how important ECs are. I focused highly on student gov, leadership class, commissioner roles, clubs, etc. and less on my grades. I got below an 1800 on my SAT in one sitting and had 3 D’s on my transcript… yet I still got accepted to UCLA and UCB. No sports ties, no family ties, or any catch. I spent a great deal of time on my ECs and also a great deal of time on my essays, and was honest about it in my personal statements. It worked for me so I personally know that you should most certainly try to be more involved in these!