People don't easily forget stories of powerful pastors taking money from vulnerable people who hope they can be cured, or that their prayers will be answered.
The decline of mainline church attendance in the U.S is a pretty well established fact. It only takes a simple Google or Yahoo search to confirm it. The hit to mainline churches far exceeds the very minimal decline of Evangelical churches.
To your question, being 'born again' is another of those things Christians say, but it's from a specific place in the Bible, namely the Gospel of John, chapter 3.