President Barack Obama's endorsement of gay marriage is being credited in part for a big drop in the number of people who say being gay is a sin.

According to a survey by the Southern Baptist-affiliated LifeWay Research, a plurality of Americans (45%) do not believe being gay is a sin. Thirty-seven percent of respondents said it was a sin, while 17 percent refused to answer. The results were reported by the Detroit Free Press.

That's a 7 percent drop since LifeWay's September 2011 survey.

Anthea Butler, associate professor of religious studies at the University of Pennsylvania, pointed to several reasons for the shift in attitudes, including Obama's May, 2012 endorsement of gay nuptials.

LifeWay's Ed Stetzer said the shift created a whole new issue.

“The culture is clearly shifting on homosexuality, and this creates a whole new issue: How will Americans deal with a minority view, strongly held by Evangelicals, Catholics, Mormons, Muslims, and so many others?” Stetzer said in releasing his group's findings.