became a labor organizer for the California Teachers Association, and campaign manager for Fabian Nuñez's campaign for California State Assembly in 2002. de León and Nuñez have been close political allies for most of their careers. California State Assembly (2006–2010) De León first ran for office in 2006 defeating Christine Chavez, the granddaughter of labor leader Cesar E. Chavez, to replace the outgoing Jackie Goldberg as the California state assemblymember for the 45th district, covering Hollywood and much of Northeast Los Angeles. In 2008, eyewitnesses on the floor of the state assembly observed de León casting a so-called ghost vote for assemblywoman Mary Hayashi on an affordable housing bill, opposite the way she would have voted, when Hayashi was away from the assembly floor. De León said he had no memory of the incident but also said he did not deny it, either. De León was investigated by then-state assembly speaker Karen Bass, but did not face any punishment and the vote was later changed. As a result of the controversy, Bass changed assembly rules to enforce a ban on ghost voting. In 2009, de León was defeated in a bid to become speaker of the California state assembly, after many assembly members found de León's ambitious nature grating, eroding his support, according to reports in the Los Angeles Times. California State Senate (2010–2018) De León was elected to the California state senate in 2010 and became state senate president pro tempore in 2014. As a California state senator, De León has been generally regarded as a liberal and describes himself as a "proud progressive." Energy and the environment De León sponsored SB 100, which would have required the state of California to generate 50% renewable electricity by 2026 and 100% renewable electricity by 2045. In 2018, the bill passed both houses of the California state legislature and was signed into law by governor Jerry Brown on September 10. In late 2017, de León was criticized for playing a role in killing a bill that would have blocked the controversial Cadiz Water Project, a proposal to mine and transfer groundwater from protected desert habitat in Eastern San Bernardino county to parts of Orange county. Opponents of the project blamed De León, then president pro tempore of the senate, and pointed out that the company behind the project had donated $5,000 to De León's political campaign. Fabian Nuñez, a close ally