He faced a number of well-connected challengers, including John Pérez, the cousin of Los Angeles mayor Antonio Villaraigosa.

Lara was subsequently appointed by Villaraigosa to the powerful Los Angeles Planning Commission, where he served until resigning to focus on his 2010 Assembly run in the 50th district.

With the support of the state and local Democratic parties as well as the Los Angeles County Federation of Labor, Lara prevailed handily.

[15] He was author of the Super Pollutant Reduction Act (Senate Bill 1383) in 2016, which created the nation's toughest law on black carbon, methane, and fluorocarbons that contribute to global warming.

[16] Lara wrote Senate Bill 4, Health for All Kids, which became the basis for 2015 budget action that led to healthcare for nearly 200,000 undocumented immigrant children under California's Medi-Cal program.

[17] In the 2017 legislative session, Lara introduced the Healthy California Act (Senate Bill 562) with Senator Toni Atkins to create a single-payer healthcare plan that replaces private insurance with a publicly run plan that covers all Californians, including an estimated 2.7 million uninsured and as many as one-third of Californians who are underinsured.

[18] He is also joint author with Senator Holly Mitchell of a package of bills to reform criminal justice and juvenile justice laws by requiring minors consult with an attorney on a Miranda warning, ensure children under age 12 are not subject to juvenile court and seal arrest records for those never convicted of a crime.

Lara has also passed bills to create cleaning product chemical disclosure, prevent California law enforcement from participating in the creation of a registry based on religion, ethnicity or national origin, and protecting the privacy of hotel guests and bus passengers.

[2] After the election, Lara faced significant criticism in which he admitted to receiving donations from the insurance industry he regulates despite pledging not to do so during his campaign.