If the people had the ability to select leaders and parties with merit and there were leaders and parties with merit to begin with in a political system then elections would all be very defined, there would be a party that came out far ahead of all others as the people would have seen what the best party was and voted for it.
This however does not seem to happen very often, most the time elections run very close, easily within a 10% difference. This would imply the opposite, that people cannot pick leaders at all and so it is essentially left to chance and like tossing a coin or that the leaders themselves are so similar that it would be like picking between two identical objects in a store, the chance would again be close to 50/50. So in yet another way democracy is a farce.