What sort of Satanist? A Laveyan Satanist? A Temple of Set Satanist? A Crowley esoteric Satanist? Or a blackmetal headbanger Satanist? Because they’re not at all the same thing.
Laveyan Satanists are not Satanists in the truest sense of the term, since they don’t believe in Satan. They’re actually neo-pagan Pan cultists of the sort which survived in the countryside of Europe well into the Middle Ages. Lavey used Satan as a kind of marketting kung fu against the christians, who stamped out Pan worship by claiming that Pan was Satan (hence the depictions of Satan as having cloven hooves, a tail, and goat horns). Lavey figured that he’d use it against them, positioning his church as the alternative to christianity. Once people got past the theatrics of the goat skulls and black candles, they’d stay for the philosophy.
The Temple of Set is an offshoot of the Laveyan Church, which views Satan as more of a spiritual force than a stand-in for Pan. They tend to be more philosophical than the Laveyan Satanists (and are connected to the esoterics through Egyptian mysticism).
The esoterics, like Crowley, draw from a wide variety of traditions, folklore, and religions, with a strong focus on Kaballah and Alchemy. Their interest in Satanism comes largely from the Catholic obsession with demonology. And again, they tend to view Satan as more of a metaphor for understanding certain elemental forces than as some dude with a Van Dyke beard and a pitchfork.
The blackmetal headbangers are probably closest to what most people think of as a Satanist, all devil-horn hand gestures and corpse paint and upside down crucifixes. They are Satanists in the same sense that punk fans are anarchists: mostly surface and for show, with the occasional “hail Satan” or Hot Topic pentagram necklace.
I don’t think any of them would be particularly successful openly, but there’s strong evidence that the Skull & Bones Society – which has produced quite a few presidents – has links to esotericism along the lines of the Rosicrucians and the Freemasons. So it’s likely that a closet Satanist would do better than an open christian evangelical.