https://en.wikipedia.org/wiki/States%27_rights#States.27_rig...
Such an overloaded term. It is also used to mean "something only some can hear, but I can't."
States have also been a source of innovation. California, Oregon, and Washington were noted as "bellwether" states, whose pioneering policies were sometimes adopted by other states. California's pollution/vehicular laws have been a force for positive change and innovation in the auto industry.
Urban California is a pretty liberal place, but rural California really isn't. Granted, I have my doubts it would be as conservative as the Deep South, but if Central California were a state of its own they'd probably repeal a number of these "pioneering" laws that cut into farm profits.
I would argue that states with a liberal voting record also likely have a majority urban population of registered voters, even if we're talking about a large state with plenty of land being used for natural resources.