At the forefront of today's culture wars are evangelical Christians. While many have found themselves a home within the Republican Party, others are leaving the faith, preferring a Protestantism. In politics, it's more accepting of debate and dissent. In her book, The Exvangelicals: Loving, Living, and Leaving the White Evangelical Church, author and National Political Correspondent for NPR, Sarah McCammon, tells us of her life being raised within a strict Midwest evangelical family and community, and explains how and why she ultimately Left of the Faith. Sarah, thanks so much for joining us tonight. Before we get too far in here for the uninitiated, what's the difference between a mainstream Protestant and an evangelical Protestant?

I think the short version is that mainline Protestantism has embraced modernity in a way that arguably evangelicalism has not. That it means things like a modern approach to science, including the acceptance of evolutionary theory, which many conservative evangelicals don't place.

You were evangelical for most of your adult life and described questioning the faith as a unraveling. What stopped making sense for you?

Really, it was most of my childhood. For me, and I talk in the book about many things that seemed off. One of them was my family's relationship with my grandfather, who was one of the few people we knew who was not religious and who came out as gay late in life. We spent a lot We had a lot of time worrying about him. We had a lot of distance from him, in part because of his sexuality. There was something about that that always felt wrong to me throughout my childhood. Also being taught creationism in my Christian school, I always wondered why we seem to believe something differently about the history of the world than most other people did and why we rejected mainstream science.

You were NPR's lead political reporter assigned to cover the Trump campaign in 2016. Because of your evangelical background, what would you say made you the right person for the job?

I'm old enough to remember the 1990s when many evangelical leaders were loudly criticizing former President Clinton for his moral failings. I couldn't help but remember some of those conversations in my own home and in my community about the importance of character in a president. I was thinking about that as I was covering this campaign. Really, just while I had my own separation from that movement, I was fascinated to see how those voters would react to Trump, how they would talk about him, and what they ultimately would do. Of course, we've seen again and again that the white evangelical movement has embraced Trump.

Former President Trump didn't appear to be the type of candidate evangelicals could get behind, yet they did and still do. I remember that time when he was asked, What's your favorite chapter in the Bible or scripture? He was just like, Oh, the whole thing. Then he said, Two Corinthians rather than like, Second Corinthians. There were several examples of him not necessarily being really a religious person. Why do you think that the evangelicals were so eager to support Trump in particular? Not even just say, Oh, we normally back Republicans because of the conservative beliefs, but this was specific to support Trump.

Well, based on my reporting, my sense from talking to voters was that they felt and had felt for a long time that the country was on the decline line. I cite in my book some of the textbooks I read in Christian school that talked about America as a Christian nation that was specifically called and designed by God to be a certain way. Usually, that was a pretty traditional view of families. There was this very glowing view that was presented to a lot of white evangelicals for many years about the history of the country and a sense that anything that was going wrong in the country was a result of falling away from that, falling away from Christianity. This was a theme I heard a lot growing up. I think when Trump talked about making America great again, and he explicitly promised to stand up for Christians, he said that many times, including recently, that resonated with a lot of people. I think they didn't fundamentally care that much about his character. We would hear things like, We want a politician. He's a politician, not a pastor. Trump was in search of a base that he could mobilize, and The Evangelicals were an easily mobilized base who were in search of a champion for their ideas.

He promised to do the things that they wanted, and he did in many cases.

Sarah, we thank you so much for joining us. I want to let our viewers know that Sarah McCammon's book, The Exvangelicals, Loving, Living, and Leaving the White Evangelical Church, is now on sale and available wherever books are sold.

Hi, everyone.

George Stefanopouls here. Thanks for checking out the ABC News YouTube channel. If you'd like to get more videos, show highlights, and watch live event coverage, click on the here to subscribe to our channel. Don't forget to download the ABC News app for breaking news alerts. Thanks for watching.