"The Journey"

I told a friend I really liked this one church in town, except I kind of get exhausted by so much talk about "the journey." I was only joking, tongue-in-cheek, really, but then I saw this article about a church in St. Louis literally called The Journey. It's about a church that is probably becoming more and more common. It's a church that, on the one hand, seems very comfortable with preaching and teaching historic views on faith and spirituality, but on the other hand, is very uncomfortable with the complete superimposition of evangelicalism with Republican politics in the United States (here here). Here the article has some hard facts to back it up.

“Evangelicalism is becoming somewhat less coherent as a movement or as an identity,” said Christian Smith, a sociology professor at the University of Notre Dame. “Younger people don’t even want the label anymore. They don’t believe the main goal of the church is to be political.”

About 17 percent of the nation’s 55 million adult evangelicals are between the ages of 18 and 29, and many are troubled by the methods of the religious right and its close ties to the Republican Party.

In a January 2007 survey of 1,000 young people for the book “Unchristian,” one of its authors, David Kinnaman, president of the Barna Group, which studies Christian trends, found that 47 percent of born-again Christians ages 40 and under believed that “the political efforts of conservative Christians” posed a problem for America.

I wonder what is going on here. Why did evangelicalism become successfully tied to the Republican party? It seems like abortion had a lot to do with it. Since 1992, abortion rates have been plummeting, so maybe part of this is simply that there really are few alternatives to abortion that can credibly get evangelicals together, since "evangelicalism" is inherently so diverse on its face. It seems like gay marriage was floated as the next big Christian issue to keep the evangelical bloc together, but I can't see that one really having the strength like the former did at creating a sizeable bloc. But is abortion really it anyway? I know tons of people have studied this, but what's the main finding exactly?