I think the main problem with Public Choice Theory is the standard and ideal of "the public interest" or "the common good." So too other familiar phrases like "the greater good," "the good of all," "the good of humanity," etc. These are all naturally and inherently collectivist notions and ideals. What is needed is "the individual interest" or "the individual good." Political leaders need to promote this relentlessly. The obvious point here is everyone is an individual. The subtle point is everyone is an individual equally, and possesses equal rights.
It's worth noting that people often invoke "the public interest" as their grand and overarching social/political goal just before perpetrating some horrific injustice or act of tyranny. And just after this depravity, the miscreants and unprincipled evil-doers often claim that "the ends justify the means."
Such is the nature of this dreadful societal ideal. The inevitable result of such false and evil beliefs and lofty goals is internecine competition, civil war, destruction of the brotherhood of man, and a massive breakdown of society.
I think the Sacred Self is "the one true god." Or, at the least, he is potentially a demigod. Thus in any civilized culture or society, the personal comes before the social, and the individual before the collective. Hence the only legitimate socio-economic goal and political ideal is always "the good of the individual," or "the good of the one and only."
In any proper and virtuous world, the group or the collective -- including close relatives, friends, colleagues, neighbors, and coworkers -- necessarily comes second. Or even last, or not at all. This is because the Holy Individual is all. The totality of society and civilization should be bent to his benefit, prosperity, happiness, and triumph. Everyone lives, and experiences life, as an individual. And in this regard it needs to be established that moral individualism or egoism is not anti-social or socially destructive. Only ethical and political policies aimed at "the public interest" are.
However much politicians are subject to self-interested Public Choice Theory in which various special interests are the real motivators and beneficiaries of gov't action, political policies would be far better if we got rid of the collectivist ethical and political ideal of "the public interest/good."