If you’re a follower of Tony Perkins and the Family Research Council, it’s time to binge on those last few Twinkies.

Tuesday, April 7, is the first day of a three-week fast the social conservative leader has called so that “God will intervene to guide our Supreme Court to protect, not destroy, natural marriage as the legal standard for our nation.” It ends on April 28, the day the Supreme Court will hear oral arguments in two same-sex marriage cases.

On first blush, this sounds great to me. If fasting is an efficacious method to sway the opinion of the Almighty, then the Christian Right deserves to win. And if not, then they deserve to tire themselves out so that they can’t argue, march, picket, and yell quite as loudly. May the best worldview win!

On closer inspection, the fast is part of an increasing trend among American Evangelicals, who are quickly catching up to Orthodox Jews, Roman Catholics, Eastern Orthodox Christians, and Muslims, all of whom have fasted for religious reasons for centuries.

Back in 1998, Pat Robertson and other Evangelical leaders called for a 40-day fast to bring about a third “spiritual revival,” rivaling the Great Awakenings of the 1730s and 1800s. Interestingly, official Republican presidential candidate Rand Paul recently called for the same thing last week.

Bill Bright of Cru—formerly Campus Crusade for Christ—joined that call, and has called fasting a “spiritual atomic bomb” in a popular online brochure. Liberty University’s Elmer Towns has authored a half-dozen books on the subject, promoting the idea that fasting leads to “spiritual breakthrough,” miracles, and the like.

It should be noted that the term “fasting” covers a lot of ground, from total abstention from food and drink to relinquishment only of certain foods, like during Lent. It could even mean simply abstaining at certain times: Religious Muslims, for example, fast during the days of Ramadan, but eat (copiously) during the nights.

One of the questions associated with fasting is exactly what it accomplishes. Is fasting believed to be like magic, or, perhaps more respectfully, like a fervent prayer that moves God to respond? Or is it, instead, purely a spiritual practice, good for inspiration, grief, hope—but not necessarily precipitation?

This debate goes all the way back to the Bible.

On the one hand, as Perkins noted, Queen Esther called on the Jews of Babylon to fast for three days and as a result “the Jewish people were saved, have survived to this day and now have a reestablished nation of their own.” (Nice elision of 2,400 years of history, by the way.) Fasts are proclaimed 10 times in the Bible, often by kings and other rulers.

On the other hand, different Biblical texts scorn the idea that fasting is some kind of magical practice. Isaiah 58:5-6 has God asking, rhetorically, “Is this the kind of fast I have chosen, only a day for people to humble themselves? Is it only for bowing one’s head like a reed and for lying in sackcloth and ashes? Is that what you call a fast, a day acceptable to the Lord? Behold, this is the kind of fasting I have chosen: to loose the chains of injustice and untie the cords of the yoke, to set the oppressed free and break every yoke.”

Fasting isn’t just for politically gladhanding justices. It may be used for mourning, for introspection, even for repentance. But even for Isaiah, fasting to affect the Divine, without behavior change, is preposterous.

Perkins’s call has it both ways. It’s both meant as a “prayer that God will intervene to guide our Supreme Court” and as a personal act of penitence.

Of course, the two are related, since as one Christian blog observes, it’s our own sin that has provoked God’s wrath. So, fasting is self-abnegation is humility is repentance—and repentance appeases the Divine.

Fasting may also be gaining popularity as more earthly methods of political action appear to be failing. As Christian conservatives lose the Culture War, they are turning to help from above. And yet, at the same time fasting is, on its face, about values like submission and humility, it is also an assertion of power. (In this regard, fasting is not unlike anorexia, which is often a desperate bid for control.) Conservatives may not be able to persuade the moveable middle anymore, but they can persuade the Almighty.

These trends recur throughout the history of religion. Religious groups enter the mundane world, and depart from it—and projecting one’s power into supernal realms is a sure sign of the latter. It’s no coincidence that the apparent increase in fasting among Evangelicals (we still lack reliable data on the precise upswing) is accompanied by a strong belief in the impending apocalypse. The end of the world is nigh; now is time to fast and repent.

And because of its physiological effects, fasting also acts like a drug on the mind of the believer. Sensory input changes, insights pop, and the mind starts to feel like it does on psychedelics or extended meditation. (Fasting is popular in the New Age world as well.) This is why it has been practiced for millennia by spiritual seekers.

As part of that hallucinatory experience, people fasting for extended periods can have the sense that they are actually accomplishing something, just like a stoner feels like he can float those potato chips across the room through telepathy. You may not actually get those chips, or influence the Supreme Court, but it sure can feel like it.

All of these trends converge in modern Evangelical fasting: the intense personal spirituality, the sense of material disgust, the desperate hope that one might somehow influence the Divine to save a fallen world. It’s a simple act, not eating—and easy to ridicule as a political strategy. But beneath the surface lie all the hope, terror, and despair of the contemporary Christian Right.