No body gives you power but it is taken from the people by those that need it. It is taken from the poor, the rich, middle class, religion, ethnic groups,weaker countries etc.If you need power especially politicians and world power countries,these people can go to any length to make sure they get that power. Check out what is happening in Russia and Ukraine ,Isreal and the Palestine. Each country is showing power either by technology or man power.
The reason why politics is referred to as a dirty game is because of the actions of the political actors, they have the greed tendency and can do whatever they can just to get the position, most of the time, politicians have designed their own way to win the election even before the elections start and to execute his plans, he will be ready to take our anything that stands on his way, so we need to avoid such political practices and allow the system to work.