What does Atticus mean when he tells Scout that a person's conscience is the "one thing that doesn't abide by majority rule"?

He means that your own conscience must tell you what is right or wrong, and it does not matter how many others agree or disagree with you. As Atticus explains to Scout, this is why he is defending Tom Robinson, even though most of the town thinks he is wrong for doing it

overnment is strong when they have the ability to persuade those they govern to believe government has enough power to force them or should be forcing them to do government’s will.

when enough of the citizenry do not believe government can force them or should force them to do its bidding, government has lost or will lose its strength and power to coerce.

when enough of the citizenry do believe government can force or should force them to do its bidding, they become passive at the least or actively pro-government and repeat government’s own rhetoric to pass on what they have been persuaded by government’s propaganda.

a true majority isn’t always needed to govern or to stop government. many times all that is needed is a strong minority. if a determined 30% of the population rises up against government in a concerted effort to bring it down, this size minority usually will succeed as long as those actively opposing the minority are less in force than the minority. so if 41% of the population sits at home watching tv rooting for one side or the other, they don’t matter. it’s the active parties who make a difference.

why does the crew join ahab's quest without hesitation?