Elitism is the belief that one is superior to the common man, or that one belongs to a group that is superior to the common man.
Such a belief would not be a problem if it didn't result in such elitists feeling comfortable in imposing their values on the common man.
A current example is the attempts by those under the influence of the medical-industrial complex to force vaccines on people, particularly young children, whether they want them or not.
This kind of elitist thinking is common in government officials and among certain sections of the population who have been convinced that unelected technocratic rulers know more that we do what is best for us and that they should be allowed to override our free will and force things upon us we don't want.
The idea is that the common man is too ignorant to make wise decisions for himself and his children and that the state should intervene in getting the best results for society.
Where this kind of thinking ends will depend upon how much resistance the people put if. If they lie down and accept increased technocratic control of their lives they will end up like a domesticated animals, kept in servitude and slaughtered when it suits our masters to do so.