Choosing the delegates can be tricky because they can change their votes, so potential delegates have to prove they'll stick to their presidential candidate.
Vanessa Lugo, Clinton delegate candidate, says "You need the loyalty there and I've worked with Hillary in her campaign in Nevada and in phone banking all throughout the state."
More than 2,000 people applied to be delegates in California. The state gets 241, with 134 going for Clinton and 107 for Obama.
