Evolutionary biologist Richard Dawkins on Sunday asked how anyone could vote for a "massively gullible fool" like Mitt Romney who could not see that Mormonism's founder was a "fraud."

"Romney's prophet Joseph Smith a fraud," Dawkins said in an hours-long Twitter rant, quoting from the Book of Mormon and adding, "Romney falls for it."

"No matter how much you agree with Romney's economic policy, can you really vote for such a massively gullible fool?" the atheist asked. "He is a Mormon BISHOP!"

"Bible & Koran genuinely old, written in the language of their time. Book of Mormon written by 19thC charlatan. Romney too stupid to see it," he continued, snarking, "And it came to pass that the lot was cast for Mitt and Mitt did verily reign in the land and there was rejoicing in the corridors of Mammon."

According to The Daily Beast's Andrew Sullivan, Mormons differ from most Christians in that they see no conflict in serving God and mammon -- or material wealth that many mainstream believers view as diminishing religion.

"Could you really vote for a man who thinks the Garden of Eden was in Missouri?" he asked again three hours after the tirade began.

In a comment on his website, Dawkins responded to the criticism that he had singled out Romney's Mormonism when President Barack Obama was also a religious man.

"There seems a good chance that Obama is an atheist," he wrote. "The fact that he professes Christianity means nothing. He's an elected American politician and if you fail to profess some kind of religion you are not an elected American politician. ... Romney, on the other hand, seems almost certainly a true believer. He was a zealous Mormon bishop."

"Christianity, even fundamentalist Christianity, is substantially less ridiculous than Mormonism (and Obama, if he is Christian at all, is certainly not fundamentalist)," he explained. " The idea that Jesus visited America is preposterous, and the idea the Adam and Eve did too is even worse (it is at least arguable that Jesus existed). The traditional Mormon belief in the inferiority of black people (only lately renounced for reasons of political expediency) is as scientifically inaccurate as it is obnoxious.The great 'prophet' Brigham Young even prescribed the death penalty for inter-racial marriage."

Dawkins concluded: "No, in the best of all possible worlds we don't want a Christian President, but in the world of political expediency we are probably going to have to live with a President who at least pretends to be Christian. We most emphatically do NOT want a Mormon President, and there seems very little hope that Mitt Romney is only pretending to be Mormon."

(h/t: The Telegraph)