What do you think the story of "The Lottery" symbolizes?
The story "The Lottery" symbolizes inhumanity and the inability to question the status quo. You have here a group of people who, for no reason they can actually explain, have continued a morbid practice in town, which is to elect someone for stoning them to death.
There is no religious, political, or even logical reason for this practice. The elders themselves explain that it just "needs to be done" without giving a specific reason but that it has been the practice to date.
Therefore, the lack of explanation, the lack of logic, and the lack of humanity in this practice is what tells you that the lottery is a symbol of what happens when there is no leader, and only followers.