The United States Census in a key determining factor in the apportionment process for the establishing the number of seats each state is to have in the US House of Representatives. It calculates the total population of each state, which is how the US House of Representation membership is established. However, the process by which actual members are appointed to the US House of Representatives is much more complex.
The United States Constitution guarantees that each state is to have at least one delegate in the US House of Representatives, regardless of what that state's actual population may be. This means that out of the established 435 seats in the US House of Representatives, a total of 385 seats will be apportioned using the proportion of population to the number of representatives. Generally speaking, the more populous a state is, the more seats it is to have in the US House of Representatives.
However, the actual methods used to determine actual representation are based on mathematical applications. Currently, the system employed is known as the equal proportions method. Since the establishment of apportionment was introduced, there have been five methods of apportionment that have been employed in delegating state representation in the US House of Representatives.
Congress is responsible of appointing the method to be used to calculate apportionment. Since 1941, the method used by Congress is the equal proportions method. The equal proportions method has, as its first step, the consideration that the Constitution allows for each state one representative, regardless of actual population numbers. Therefore, fifty of the 435 seats in the US House of Representatives are already accounted for. This leaves for 385 to be apportioned.
The equal proportion method, because of its inherent mathematical process, also provides for a listing states to a priority value. In other words, the first seat to be assigned under this method is delegated to California, because it is the most populous state. Seats are distributed one at a time using a formula that uses the ratio of the state population to the geometric mean of the seats that state currently holds in the apportionment process.
For example, under the equal proportion method, California would be assigned the 51st seat, the first seat allocated after the initial fifty. In obtaining the 51st seat, California at this point already has two seats in the US House of Representatives. In the mathematical computation of the formula, California's priority value would decreased, and be positioned last in line for the next seat assignment. The 52nd seat would go to Texas, for the computation would render its priority value highest at this point.
However, California also receives the 53rd because at this point in time, it holds a higher priority value than all of the other states. Therefore, each time a seat is delegated to a state, the priority value is reduced, and states are reordered according the next highest priority value in line.
It has yet to be proven possible to calculate a fair distribution of voting power throughout the states due to the size of electoral districts. The equal proportions method has been determined by Congress as the most viable method.
All methods that have been used for the apportionment of the US House of Representatives have been susceptible to what is known as the apportionment paradox. The apportionment paradox essentially details the possibility of state actually losing a seat in the US House of Representatives due population growths. For example, it is possible for a small state with a rapid population growth to lose a seat to a state with larger experiencing a slower population growth.