Stories of devil-worshippers existed in the middle ages and later but were largely folkloric and did not describe genuine religious practices.
However, there have been a few branches of religious belief which involve the worship of Satan.
In Sweden, where the process of Christianization lasted into the second millenium AD, there is evidence that Satan received a degree of popular worship into the early modern era as an ambivalent or even benign spirit of nature, possibly the result of the Judeo-Christian figure blending with traces of local pagan deities.
Testimonies from the trials of alleged sorcerers in seventeenth-century Sweden, meanwhile, equate Satan with various traditional nature spirits.
Historian Mikael Häll points out that many of these people were outlaws living in the woods, and speculates that they may have adopted Satan as a sort of patron spirit.
He concludes that, while it is unlikely that there was an organised cult of devil-worship in Sweden at the time, there were people who could be termed Satanists.
Satanists typically eschew mainstream politics, for what should be obvious reasons.
As of late, with a number of Supreme Court rulings granting unprecedented power to Christian groups in the name of religious freedom, some Satanic groups have decided to test the limits of these rulings by asserting that, as religious organizations, they too have the right to, say, hold Black Masses in civic centers, As of early 2016 the Satanic Temple wanted to give an invocation at the Council of Phoenix Arizona.
Some Councillors wanted only a rota of council approved clergy to give invocations.The Freedom From Religion Foundation planned legal action if the First Amendment is breached.While these actions by Satanic Temple are often little more than publicity stunts, they (especially the reactions of Christian leaders) do wonders at showcasing the hypocrisy of the religious right when they try to claim that they just support religious freedom as opposed to theocracy.With the majority of the American population at least nominally Christian, not only would an avowed Satanist never stand a chance running for any elected office, but a candidate merely receiving endorsements and/or donations from Satanists would have to explain him or herself to voters as though he or she had been endorsed by the Ku Klux Klan.However, when asked to describe what they believe, many Satanists voice political views that are in line with some form of heterodox libertarianism.This is roughly in keeping with both the theology and culture of Satanism — it emerged from the same '60s counterculture that the modern libertarian movement did, it is at best begrudgingly tolerant of Christianity, and it is very supportive of libertarian beliefs in personal freedom, while its heavy emphasis on individualism often leads to dismissal of ideologies that are seen as promoting collective or hierarchical authority.