California is already gerrymandered to the extreme. The state is already set up to favor Dems, and it does, but the price they pay for their majority and safe districts is that the GOP also has their own safe districts.
Plus, didn’t Prop 11 pass in California? If it did in fact pass, then re-districting would be in the hands of a non-partisan citizen’s panel, not the legislature.
Prop 11 only applies to the state legislature; Congress was specifically excluded in order to draw in enough Democratic support to allow it to pass.