During the second half of the last century the idea that political science should be treated as a science became extremely popular among academics, especially in the United States. One of the most important exponents of this school of thought was Anthony Downs, who developed a theorem to explain, in a rather economic sense, how and why voters behave in a certain way when it comes to voting. Downs not only applied his theory to the way voters behave, but also used it to explain the way political parties align when it comes to elections in a two-party and multi-party system, however this essay will analyze Downs' claims about a two-party system. only. This essay argues that Down's model has proven accurate in many cases throughout history, yet it makes a number of assumptions about voters and parties that cannot be considered realistic even in 1957, when he published his article An Economic Theory of Political Action in Democracy in 1957 nor in 2013. This essay also acknowledges the fact that this theory might help explain how parties behave, but it is by no means the only explanation. Furthermore, this essay will demonstrate that it is a multiplicity of factors, rather than an economic theory, that can help us understand why parties behave in a certain way. To support the argument set out above, this essay will state and critically analyze a series of Down's assumptions, then his theory will be outlined. It will then carefully evaluate how effective it was at predicting how parties align by examining the behavior of political parties during general elections in different countries. ...... middle of the paper ...... n lead to a party that does not move towards the center like imperfect knowledge. The conclusion can be drawn that, as is the case with many other general explanations about politics, the Down model can only explain to a certain extent how parties align in general elections. Decisions made by political parties are made indirectly by humans, and the way humans behave and act will never be explained by a single factor or model, especially one that assumes that human complexity can be simplified by economics . A possible field of further research would be to investigate the different ways in which the use of new technologies and social media can give political parties a clearer and, above all, constant and interactive view of what the electorate thinks, in based on the policies that are most discussed on social platforms such as Twitter or Facebook.