Here is a simple, successful election. The graph shows how many voters are at each point on the political spectrum. It also shows the positions of the candidates. The Good candidate is the one whose opinions are closest to the will of the voters.
Voters choose the candidate that is closest to their own position, so the Good candidate wins.
The dividing line shows where the vote splits. Voters to the left of the line will vote for the Good candidate, voters to the right of the line will vote for the Bad candidate.