A big focus for Sanders during this trip was selling his proposed Medicare-for-all health care legislation.
"If we win here in California, and we can win here in California with your help," said Sanders to a packed crowd at the Montalban theater in Hollywood. "I think we've got a straight path to victory."
Sanders is currently polling near the top in California.
Meanwhile, Mayor Buttigieg from South Bend, Indiana, used his visit to speak about the Douglass Plan, part of a proposal to tackle systemic racism.
The openly-gay candidate has had a tough time connecting with African-American voters and he addressed that head-on during an appearance at a co-working space in the Crenshaw district called Vector 90, which was co-founded by the late rapper Nipsey Hussle.
"In order to earn support, you have to build trust, and especially in communities in color, where you are new on the scene and not yourself from a community of color, you got to work a lot to make sure that your vision is understood."
Buttigieg and Sanders will face-off in the second round of debates in the Democratic Party, hosted by CNN, in Detroit on July 30.