If you were to tell an ordinary person that leftism is evil (not that I go around saying this), most would look at you as though you were mad. The standard modern view of both self-identified left and so-called right is that liberal values, which are those of the left, are enlightened values. Even most spiritual but not religious people would think like this. But they're wrong and here's why.
What leftism does is transfer the idea of the good from the spiritual realm to the material plane. That is what actually defines it. This means that the good, insofar as it concerns humanity, now relates almost completely to the body and the emotions, with what pleases me and gives me happiness being seen as good as long as it doesn't interfere with someone else's body or emotions. Correspondingly, evil is what causes suffering on a bodily or emotional level. This makes God, if he exists, either evil himself or uncaring. This spiritual sleight of hand is only accomplished by totally ignoring the higher world or, if it is accepted, it is seen only in the light of this one. The consequence of that is that the transcendental values of the Good, the Beautiful and the True are denied, with the vision of the absolute dismissed so that everything becomes relative and this worldly. In this way leftism denies the real good and replaces it with a false one. What denies good is evil.
The modern world has no understanding of good and evil. But since good and evil exist it must necessarily project the fact of these realities onto something else. So, it thinks it knows good and evil but it assigns their being in the wrong place and not infrequently actually inverts them. This all comes down to a false understanding of what man is. If man is identified as a material being then good is what benefits him in that aspect. However, if he is identified as a spiritual being, a soul, then the situation is very different. Good is what advances him as a spiritual being with evil what hinders or prevents that advance. Treating him as a material being and taking steps to encourage and support that identification would certainly hinder the spiritual side of things. This makes it evil.
To know real good, you must acknowledge God. If you have no understanding of an absolute good, something real in which good is focused, then any concept of good is purely relative which means it is an arbitrary thing with no substance. We no longer know good because we don't acknowledge God, and, not knowing good, we don't know evil which means we are easily vulnerable to it.
Over many decades the left has been used to deny reality. As Bruce Charlton pointed out in a post today (see here), it has consistently set about labelling most of humanity's natural intuitions about life as bad because in some way they exclude though everything excludes on some level. If it didn't there would be nothing. Exclusion is the very nature of form. This, it must be stressed, is not just an honest mistake. It is a quite deliberate attempt to mislead and corrupt. If not on the part of the ordinary man or woman then very definitely on a supernatural level which is the level from where the whole thing is organised. And even the ordinary person is not blameless for if their heart was in the right place and their mind correctly ordered they would not go along with the distortion of truth.
Leftism is the attempt by forces antithetical to God to turn human beings away from spiritual truth towards atheism and materialism. It has been extraordinarily successful. There is no longer any point in being polite about this or looking for excuses. The situation has gone too far and seeks to go further with every year that goes by. The left is demonic and if you don't see that you need to start waking up.