People think the objective is to find out who is mafia. The best way to accomplish this objective is to rule out who is legit. Depending on the results, you can find out players who are legit on Day 1. Sometimes, you can get 1-2 legit players right away. From there, you can know that their results are gold on Day 2. Once you figure out what role they are, it makes it more difficult for the mafia to forge a role and it narrows down the field real quick.
In fact, the best case scenario for mafia is where they can make all players have a scenario in which they are mafia.
A government big enough to give you everything you want, is strong enough to take everything you have. -MLK