One of the first move that Mahathir did was to make the Anti-corruption agency and Election Commission independent agencies; they no longer work under the PM.
Even Mudlanders, who are supposedly stupid, can see the need to have independent agencies.
CPIB and Election Department are two important pillars of our society ...they should not be controlled by the PM. The reason why we don't have corruption in high places is the PM have a say on who can be prosecuted. The reason why the PAP wins election is because the PM runs the election.