It is said that evil often proclaims itself as such in some way. This may be because the law of free will dictates that if people are to be corrupted they must have some clue that this is the case. Within that criterion though there is ample scope for evil to disguise itself as good to the eye of one who does not wish to see beneath the surface and, on some level, actively wants to be taken in because this will justify some sin or fallen desire.
In occultism the left hand path is the path of transgression, black magic and sexual licence. Often rebranded as a short cut to enlightenment, crazy wisdom, breaking the rules for greater freedom, rising above good and evil and other pseudo-glamorous deceptive descriptions, it is, in fact, the path that leads away from God and towards not God which is all that rejects God and the natural boundaries and standards of his creation. This ends up, if pursued and unrepented, in a spiritual state analogous to hell because hell is nothing more nor less than separation from God. That is a state in which light must be stolen as the soul can no longer get it directly from God. A soul has to fall a long way before that will happen but if it persists on the left hand path and does not turn back to its Maker that is what will happen.
The left has long been associated with the unnatural and the dark side of life. Obviously this is not the case literally but symbolically there is a certain truth to the idea. We take our modern usage from the time of the French Revolution when supporters of the monarchy sat on the right in the National Assembly and supporters of the revolution sat on the left. A pure coincidence you might think but those who are symbolically minded will see more to it than that. We are being told something. None of this means that elements of what became the Revolution, which term I am using to mean the overturning of traditional ideas in the 18th century, were not genuinely progressive. Human consciousness was evolving. The relationship between all sections of society from aristocrats to the ordinary people and between men and women had to be adjusted in the light of greater self-consciousness. Not to mention that a new approach to religion was called for with a greater emphasis on internal enquiry. But the whole process was hijacked and continues to be, and the clue to the hijacking was right there at the beginning.
The hallmark of Satanism is rejection of God and the order of creation. This involves undermining and then inverting all natural hierarchies and if you look at the last couple of centuries, and especially the last 50 years, you simply cannot help but see this as the underlying tendency of the left. It moves from one group to another but always with the aim of subverting the natural order. The excuse is compassion or justice but the real motive is resentment and even hatred of God.
It would clearly be absurd to say that every leftist is a Satanist but every one has allied him or herself to a degree with the Satanic agenda and has done so because of spiritual failings. At the bare minimum every one is a dupe of some kind. And note that when I talk of Satan I am not talking of an individual being though there may well be such. But the prime manifestation of this impulse is the tendency in the created individual motivated by corrupted desire and badly turned will to want to sit on God's throne. This is what is behind the left, particularly as it is in our day.