In recent years, there have been skirmishes that have highlighted differences between the two groups. In 2007, David M. Hoffeditz, who was identified with the more conservative faction on the faculty, was “terminated for cause,” as Mr. Weinstein, the spokesman, put it. Some conservatives felt that Dr. Hoffeditz had been unfairly singled out by the less conservative faction, and Dr. Hoffeditz sued for wrongful termination. The episode prompted a long report by the American Association of University Professors, a nonpartisan organization, critical of Cedarville’s action.

Now, some say, the more conservative faction is having its revenge. In an interview, Dr. Brown, the president, offered a wan explanation for his departure, saying that “it’s a long story.” When asked why Dr. Ruby had resigned, Dr. Brown said, “I really don’t know,” explaining that Dr. Ruby reported to the provost. Meanwhile, philosophy has been eliminated as a major, which will most likely mean the departure of Shawn Graves, the untenured half of the duo that wrote the anti-Romney editorial.

In an interview this week, Dr. Ruby would not say why he left.

But a longtime faculty member, who asked not to be identified for fear of losing his job, enumerated several factors that may have sealed Dr. Ruby’s fate. In an interview at Young’s Jersey Dairy, a landmark hangout in nearby Yellow Springs, he said that in 2007, when Soul Force, a gay rights group, announced that its “Equality Ride” would stop at Cedarville’s campus, Dr. Ruby was, some felt, a bit too welcoming. He helped organize a series of chapel talks about homosexuality, and he encouraged Cedarville students to welcome Soul Force with love.

Dr. Ruby told me, “The Bible condemns homosexual acts, but we also thought that this was an opportunity to teach our students how to gracefully engage those with whom we may disagree.”

Dr. Ruby also conceded that in 2008, he gave in to pressure from university officials to cancel an invitation he had extended to the evangelical Christian writer and activist Shane Claiborne, the author of “The Irresistible Revolution: Living as an Ordinary Radical.” Mr. Claiborne’s teachings against war and poverty struck some critics as incompatible with Cedarville’s conservative message.

Finally, students said that Dr. Ruby was well known on campus for his compassion toward students, including those who thought they might be gay or lesbian. David Olsen, a member of the class of 1984 who is now openly gay, said that although he and Dr. Ruby differ on the morality of gay sex, current gay and lesbian students considered Dr. Ruby an ally, concerned that they be treated with compassion.

Over coffee at Stoney Creek Roasters, in the village of Cedarville, Mr. Weston, the senior, and two friends all said they missed Dr. Ruby.

“Ruby really cared about students,” said Zach Schneider, a junior computer science major.

Joshua Steele, a senior, added: “He is very real. He was aware that to everyone else we’re just the crazy Christians, and he wants us to be sincere engagers with the culture.”