two parties, "a" and "b" contend for election, "a" wins by 51% to 49% of the vote.
"b" commences to think. they identify a group that voted for "a" at least large enough to change the result, perhaps only 1% of the electorate . "b" offers this group a special favor. it might be a tax benefit, or support for private schools. the group changes it's voting habit, "b" wins. all tax payers must pay a little more. "a" commences to think, etc.
the inevitable result is a tangled tax code, a hobbled economy, and a community divided by well-founded suspicion that others are getting better treatment.
in an actual democracy, taxes have to assented to directly by half plus one of the entire electorate, special favors can't be hidden. better yet, administrators don't have financial favors to give. instead, they must hold their jobs with efficient service and probity.