In a somewhat metaphorical but nonetheless very real sense - most politics is effectively snake oil.

There's a set of people who exhibit a particular combination of mental illness and natural charisma, such that they feel an irrational urge to impose their wills on others, a lack of the necessary empathy to recognize the harm they do and the personal appeal necessary to convince others to let them do it.

There's another set of people who feel an irrational sense of helplessness - who want to turn control of their lives and their decisions over to others, so they can just go along with a preordained set of values and beliefs and choices rather expending effort on, and taking the risk of, making their own.

And just as in any more standard "snake oil" dynamic, the first group, exclusively for its own benefit, preys upon the weakness and hope of the second. Just as in any other such dynamic, the people of the first group make promises they have no intention of keeping ultimately just so that they can benefit, and the people of the second group continue, irratiomally, to believe those promises, even as all of the available evidence demonstrates that the promises are empty.