Original sentence: , powerful corporate interests behind the  act as a filter that, statistically, only lets preordained views be heard by the public and excludes third parties and alternative viewpoints., the two big political parties are both sponsored by essentially the same large corporations (such as Microsoft, Coca-Cola, McDonnell-Douglas, ...), thereby representing the interests of a tiny minority of citizens (the richest few percent) and no political parties representing the vast majority of relatively poor citizens have any realistic chance of having their political platforms presented to the public through the corporate controlled media.In this sense, they argue that the U.They point out that in the U.has what is in practice a one-party political system
Edited sentence: , powerful corporate interests behind the  act as a filter that only lets preordained views be heard by the public and excludes third parties and alternative viewpoints