Unfortunately, we have to get lucky that the majority is ethical and that is a big risk.
Very true, especially in a democracy. There's a little breakdown of the necessity of government I like to refer back to:
Logically, there are four possibilities as to the mixture of good and evil people in the world:
All men are moral.
All men are immoral.
The majority of men are immoral, and a minority moral.
The majority of men are moral, and a minority immoral.
(A perfect balance of good and evil is practically impossible.)
In the first case (all men are moral), the government is obviously not needed, since evil cannot exist.
In the second case (all men are immoral), the government cannot be permitted to exist for one simple reason. The government, it is generally argued, must exist because there are evil people in the world who desire to inflict harm, and who can only be restrained through fear of government retribution (police, prisons et al). A corollary of this argument is that the less retribution these people fear, the more evil they will do.
However, the government itself is not subject to any force or retribution, but is a law unto itself. Even in Western democracies, how many policemen and politicians go to jail?
Thus if evil people wish to do harm, but are only restrained by force, then society can never permit a government to exist, because evil people will work feverishly to grab control of that government, in order to do evil and avoid retribution. In a society of pure evil, then, the only hope for stability would be a state of nature, where a general arming and fear of retribution would blunt the evil intents of disparate groups. As is the case between nuclear-armed nations, a “balance of power” breeds peace.
The third possibility is that most people are evil, and only a few are good. If that is the case, then the government also cannot be permitted to exist, since the majority of those in control of the government will be evil, and will rule despotically over the good minority. Democracy in particular cannot be permitted, since the minority of good people would be subjugated to the democratic control of the evil majority. Evil people, who wish to do harm without fear of retribution, would inevitably control the government, and use its power to do evil free of the fear of consequences.
Good people do not act morally because they fear retribution, but because they love virtue and peace of mind – and thus, unlike evil people, they have little to gain by controlling the government. In this scenario, then, the government will inevitably be controlled by a majority of evil people who will rule over all, to the detriment of all moral people.
The fourth option is that most people are good, and only a few are evil. This possibility is subject to the same problems outlined above, notably that evil people will always want to gain control over the government, in order to shield themselves from just retaliation for their crimes. This option only changes the appearance of democracy: because the majority of people are good, evil power-seekers must lie to them in order to gain power, and then, after achieving public office, will immediately break faith and pursue their own corrupt agendas, enforcing their wills through the police and the military. (This is the current situation in democracies, of course.) Thus the government remains the greatest prize to the most evil men, who will quickly gain control over its awesome power – to the detriment of all good souls – and so the government cannot be permitted to exist in this scenario either.
It is clear, then, that there is no situation under which a government can logically or morally be allowed to exist.