Democrats control the Assembly and the Senate in California’s Legislature by wide margins that exceed the “supermajority” (two-thirds) threshold. This matters because the state Constitution, as amended by many ballot propositions over the decades, sets a high bar for making some, though not all, budget decisions and policy choices in the Legislature.
For example, the annual budget package generally may be passed by a simple majority vote of each house of the Legislature, as determined by Proposition 25 of 2010. In contrast, any tax increase requires a two-thirds vote of each house under the provisions of Prop. 26 of 2010. Prop. 26 expanded the definition of a tax increase and thus the scope of the two-thirds vote requirement, which was originally imposed by Prop. 13 of 1978. Prior to Prop. 26, bills that increased some taxes but reduced others by an equal or larger amount could be passed by a simple majority vote of each house. Other actions, such as placing constitutional amendments or general obligation bonds on the statewide ballot, also require a two-thirds vote of each house.
Here is what party control of California’s legislative seats looks like as of September 2021.