Reynolds v. Sims in 1964 made the huge mistake of prohibiting states from having federal-style bicameral congresses. How this could be unconstitutional when the federal government operates this way is a mystery.
A true bicameral congress gives each sub-government (counties in the context of a state, states in the context of the US as a whole) an equal vote in the senate and a vote proportional to their population in the house of representatives. The whole point of having a bicameral congress is to protect views that are in the minority, since the views and needs of smaller counties are markedly different from the needs and views of much larger counties.
The supreme court of under Earl Warren massively misrepresented the constitution and the effects that their decision would have on states. Reynolds v. Sims required a host of states to restructure their legislatures so that both houses were proportioned based on population - fake bicameral legislatures. Now large counties steam roll smaller counties as the interests of cities drown out the interests of the countryside.
Its important to note that changing back to a bicameral congress would *not* give small counties more representation per capita than larger counties. It would only mean that laws would have a higher bar to pass - both large and small counties would have to agree on a bill for it to pass. Currently, small counties have almost no power to object to laws.
When people are disenfranchised like this, they understandably get upset. This is why you get absurd ideas like "split California into 6 states". This wouldn't even solve the problem unless those new states also create real bicameral legislatures.
The original federal bicameralism was etched into the constitution because smaller states rightly thought that a single-house legislature would mean they wouldn't have a say. That's what we're giving to small counties now.
Bring back bicameralism to California, and eventually all states.