The two are mutually exclusive. There is no such thing as a moral ruler, any more than there can be a free lunch.
It's true that some government people - rulers - are less vicious than others. There are degrees of evil. But when media such as The Guardian remark that the newly selected Prime Minister in Britain is "unpredictable [in] that she has always been driven less by ideology than by morality, a very personal sense of right or wrong" it tells us a great deal more about the morality of the journalist than about that of Theresa May.
From her record while in charge of policing the UK, I'd say that she does tend to be among the "less vicious" kind of ruler - though, time will tell. She reduced the degree of spying on people that had been put in place by her Leftist predecessors, for example. But her "sense of right and wrong" did not lead her to question, even, the very existence of police as a class of specially authorized people, nor of government that uses powers that no real person has.
An accurate account of ruler "morality" came this month from the pen of Professor Hans-Hermann Hoppe, and I'm glad to be able to commend this excellent article after having had to point out his earlier, serious error in supposing that the payment of taxes brings some kind of entitlement. (How could it, possibly, when no contract exists?!)
But his remarks about the EU, which call it "Economically and Morally Perverse" almost make up for it - and apply not just to that outfit but to all governments everywhere. "They use democratic elections to legitimize the taxing of productive people for the benefit of unproductive people" - notably themselves, of course. Economically perverse, for it's a system that rewards indolence and punishes diligence, but also morally perverse, in that it steals some of the fruits of labor and so is a kind of partial slavery.
How, though, are moral standards to be determined? - I just suggested that slavery is immoral; but by some standards slavery is not. The Christian one, for example, does not condemn slavery per se. In his letter to Christians at Ephesus, Paul enjoins slaves to obey their masters with respect, fear and sincerity - and masters to treat their slaves, likewise, with respect. That's lipstick on the pig; it has no shadow of a suggestion that masters should liberate their slaves, or that "respect" is to include the acknowledgement that every person rightfully owns himself and nobody else. Hence, the Christian moral standard is clearly inferior to the rational anarchist ethic, of universal self-ownership.
We need not rely, though, on opinions about which ethical standard is "higher" or "inferior" to others; we can fix the matter by reference to that fundamental axiom, of self ownership. Since every person has the right to his own life, he has none to anyone else's; and therefore, the very action of ruling someone else, however benevolently, is repugnant to rational ethics. That standard alone is consistent with human nature; all others are not. The first thing to derive from that axiom is that government in all its manifestations is wholly immoral. Consequently it is impossible for a governor (ruler) to be moral, any more than a rapist or thief could be moral; each would be a perfect example of an oxymoron.
Modern rulers like to claim the moral "high ground" by bypassing all that simple, adequate and devastating logic and pointing instead to their supposed role in helping those unable to help themselves. Is it not moral and compassionate, they plead, that the unfortunate should be assisted? At the expense of the wealthy? As an entitlement? Hence Bush-I's famous remark at his Inaugural about a "kinder, gentler" society.
The appeal here springs from the view that morality has to do with sacrifice. The rich "ought" to sacrifice some of their property, to assist the poor (and if they don't, the rulers will force them to do so.) The basis for this lies, again, in Christian ethics; specifically in John 15:13, "Greater love hath no man than this: that he lay down his life for his friends." That's a verse often quoted on war memorials, to convey the fiction that the victims of government wars volunteered to die in place of their friends, even though they frequently didn't volunteer and were actually dying for their government, which is never anybody's friend.
This idea that morality centers on self-sacrifice is riddled with inconsistency. First, if moral goodness can be achieved only by sacrificing oneself to others, once those "others" are restored so that there are none left, moral goodness would become impossible. Morality, therefore, could exist only if there was a constant stream of people needing sacrifices by someone else! Second, the (say) half of humanity in need of such assistance would be for ever condemned not to be morally good; ie, the poor and needy would have to be defined as evil. That would mean that "goodness" is necessarily promoting "badness" and so the entire system becomes self-defeating and contradictory. It is truly amazing that the equation of self-sacrifice and high morality has had such a long run. High time to deep-six it.
In contrast there is what Ayn Rand called "the virtue of selfishness" - though I wish she had named it the virtue of self-sufficiency. To look after one's own needs first and foremost is highly ethical, for it removes all suggestion that someone else carries any obligation to do the job instead. The residual few who are unable to do that are then properly open to help by generous and able people who will choose do so with no compulsion at all.
Occasionally, government people tell the truth; and nobody told the truth about rulers' morality more accurately than Robespierre, in 1794: "the attribute of popular government in revolution is at one and the same time virtue and terror; virtue without which terror is fatal, terror without which virtue is impotent." In their book, force and good ethics go together; in ours, force is incompatible with good ethics. These can not be reconciled; they are utterly opposed. If any reader happens to be employed by government, please quit. TinyURL.com/QuitGov shows more.