The Ship of State analogy, which argues the unreasonable nature of choosing a likeable, but unqualified individual to captain a ship responsible for dozens of other lives.
Socrates believed that only those who had thought about issues rationally and deeply should be allowed to vote in matters of society.
His argument, was that without this connection to wisdom, populations will end up voting for demagogues (those who seek support by appealing to people’s desires, rather than through rational argument).