When you say “communication system,” I assume that you are talking about the mass media, not about things like cell phone networks or email. If so, at least in the case of the United States and other democratic countries, this is (in my view) an excessively cynical point of view that does not really conform with reality.
It is true that politicians use the media to get their messages out to the people. However, the media is not simply putting out the politicians’ messages without any regard to the truth. Politicians cannot simply say what they want and have the media accept it wholeheartedly. If that were the case, conservative media would, for example, be 100% behind Marco Rubio’s immigration proposals. There would be no criticisms of President Obama from the New York Times. But this is simply not true. It is not as if any politician can simply use the news media and expect it to do his or her bidding.
There may be countries where this point of view is accurate, but it is not accurate in the United States.