Due to a series of Supreme Court decsions in the 1960's the states were orered to disconinue allowing the counties to be equally represented in their state senates.
The states are equally represent in the U.S. Senate and the Counties should be equally represemted in the states.
The federal government does not have the constitutional authority to dictate how states must organize their state legislatures. The U.S. Constitution, under the Tenth Amendment, reserves powers not delegated to the federal government to the states or the people. Article IV, Section 4 guarantees each state a "Republican Form of Government," but this does not grant Congress the power to prescribe the specific structure of state legislatures. The Supreme Court has historically interpreted this clause as largely non-justiciable, leaving states significant autonomy to determine their legislative structures, as seen in cases like Luther v. Borden (1849). States have broad discretion to organize their legislatures, provided they adhere to general republican principles and other constitutional requirements, such as equal protection under the Fourteenth Amendment.