THE Southern Baptist Convention is the largest Protestant group in America. It claims about 16m members, and long ago spread beyond its geographical origins to every state in the union. But since around 1990 the denomination has been losing ground, relative to America's population, to other evangelical churches. So a cadre of Young Turks are looking back to the 16th century for fresh inspiration.

According to Lifeway Research, the SBC's statistical arm, 10% of all SBC pastors now identify themselves as Calvinists. And that proportion could well rise; a third of recent graduates from SBC seminaries espouse doctrines that hark back to the reformer John Calvin, with the Southern Baptist Theological Seminary in Louisville, Kentucky, a particular source. The SBC evicted its theological liberals back in the 1980s; now, war has been joined between the conservatives.

Calvinism emphasises that Jesus died only for the elect; Baptists believe Jesus died for everyone. Baptists, by definition, believe that baptism must be an informed choice by the individual, therefore limited to adults; Calvinists believe infants may be baptised. Calvinists think that God selects certain people for damnation; Baptists are more easy-going.

“You have a seismic shift in the SBC,” says Wade Burleson, an Oklahoma pastor whose “Grace and Truth to You” blog is a rallying point for the neo-Calvinists. “Change is happening at the SBC and the older established leadership isn't getting it. It's becoming far more Reformed theologically than what some are used to. The old guard is dying and retiring and the new guard is young and Reformed.”

Young Baptists are flocking to conferences that feature Calvinist teachers such as John Piper of Bethlehem Baptist church in Minneapolis, or Mark Driscoll, a flamboyant, controversial pastor who leads Seattle's largest congregation, the non-denominational Mars Hill church. Up-and- coming pastors, Mr Burleson says, are tired of a constant emphasis on numbers and church size. What converts are drawn to, he says, is theological training and rigorous Bible study.

The Baptists certainly need perking up. Their annual convention in Orlando this June drew only six reporters from the secular press. Annual baptisms in the SBC rose slightly (by 2.2%) in 2009, but total church membership dropped fractionally, to 16.2m, something once unthinkable in the denomination that produced Jimmy Carter and Bill Clinton. Sunday-school attendance, a more accurate indicator of numbers, is 7.7m, down from 8.2m in 1994.

Several Calvinists spoke at a pastors' conference before the Orlando gathering. One was the Southern Seminary's president, Al Mohler, the denomination's best-known Calvinist. Another was C.J. Mahaney, pastor of the 3,000-member Covenant Life church in the Washington, DC, suburbs, which bills itself as a “reformed-charismatic” congregation: two words that are anathema to many Southern Baptists.

Some worried Baptist leaders claim that the neo-Calvinists are rewriting the history of the 165-year-old SBC. “People try to argue that Southern Baptists have always been Calvinist and we've departed from the way in the past 80 years,” says Richard Land, president of the SBC's Ethics and Religious Liberty Commission. “That is demonstrably false.”

Mr Land is a contributor to “Whosoever Will: A Biblical and Theological Critique of Five-Point Calvinism”, which is in its fourth printing since its publication in April. He says Calvinist seminary graduates keep their beliefs below the radar when they're out applying for work, only to uncover them once safe in a job.

The Baptists have missed out on other trends, such as the 1970s charismatic movement. They now have to decide whether neo-Calvinism is a movement they can safely ignore—or whether it may take over their church.