There is no record that political pollsters in ancient Rome even knew that Jesus of Nazareth told a Jewish leader named Nicodemus that he needed to be "born again" in order see the Kingdom of God.

Germans in the Protestant Reformation embraced that "born again" image and called themselves the "evangelisch." Then in 1807, English poet Robert Southey was one of the first writers to turn the adjective "evangelical" -- think "evangelical" preaching -- into a plural noun "evangelicals." There was no earthquake in European politics.

But America changed forever when Bible Belt Democrat Jimmy Carter shocked journalists by saying that he had been "born again." That firestorm led Newsweek editors to grab a phrase from pollster George Gallup and proclaim 1976 the "Year of the Evangelical." Lots of politicos noticed, including a rising Republican star named Ronald Reagan.

The rest is a long story. 

"The news media and polling agencies realized that the 'born again' vote was a seminal political factor," noted historian Thomas Kidd, in a recent address at Wheaton College, the alma mater of the late evangelist Billy Graham.

"The Gallup organization," he added, "began asking people whether they had been 'born again.' The emergence of EVANGELICAL as a common term in news coverage of politics was a major landmark in the development of the contemporary evangelical crisis. … The media's frequent use of 'born again' and 'evangelical' connected those terms to political behavior."

More some evangelical insiders relished this attention, while denominational leaders and other mainstream evangelicals failed to realize that "they were losing control of the public's perception of their movement," said the scholar from Baylor University.

But one thing would become crystal clear, according to Kidd's new book, "Who is An Evangelical?" His bottom line: "The gospel did not make news. But politics did."