Full Idea
It is possible that the people who supported several losing candidates might have joined forces and had a majority. For that reason, many countries have a runoff election.
Gist of Idea
If several losing groups would win if they combine, a runoff seems called for
Source
Tuckness,A/Wolf,C (This is Political Philosophy [2017], 5 'Does democracy')
Book Reference
Tuckness,A / Wolf,C: 'This is Political Philosophy' [Wiley Blackwell 2017], p.123
A Reaction
The problem is that there is no rationale as to who stands in an election. If their views are evenly spread, the first result seems OK. If there are five left-wingers and one right-winger, a runoff seems to be produce a more just result.