Politics is a matter of power, control and money. As was mentioned above, all too often even worse motives than those are there, directing the way things are run. Elections are just a time of much illusion and manipulation. And remember, a party starts in one way but transforms very quickly into something totally else. In the beginning the party perhaps even did actually represent those who helped the party to be formed, but that changes soon.
People are what parties feed on.
Their money and voluntary work and trust and loyality. People believe the best and close their eyes on obvious failures and character problems and more. Especially so if the politician has managed to become a president, prime minister or so. Yes, people love those men, their lacks are not counted or even recognized. Different standards apply to the common man and rulers.