Socialism’s morality is the justification to steal for the benefit of “the poor”, when actually the money goes to the government. But whatever the reason for taking someone else’s money, there can never be a justification for breaking God’s commandment: “Thou shalt not covet thy neighbor’s goods”.
The title should be “...leftist who thinks they are morally superior.” Obviously they aren’t. Not to say that I consider myself morally superior to some of my liberal friends - but my conservative ideals are when compared to their liberal ones.