The possible weakness in a democratic political system

What we can see from the result is that the public goods for the states controlled by Party 1 are over-provided, the public goods for the states controlled by Party 2 are under-provided. If the public goods wanted by the states controlled by different parties are also different, the issues of over-provision and under-provision will become even worse. This will make people in the states controlled by Party 1 keep voting for Party 1 and people in the states controlled by Party 2 hate Party 1 and keep voting for Party 2, especially when the two parties hold very different beliefs. This could potentially make the nation split; of course, the social optimum will never be achieved under such political system.

Although there are many assumptions in the model, this proves to some degree why it is important for the entire population to be united on the critical social issues.