They're usually evangelicals. Evangelicals outnumber Catholics in the US, and also outnumber all mainline Protestent denominations (Methodist, Lutheran, etc) combined. They're fast gaining ground in Latin America as well.

Not all evangelicals are so adamantly anti-reason, but I'd be very confident in saying most are. Evangelical Christianity in the US is lazy and cruel. The Bible is used to justify their worst impulses, while they ignore all the parts about loving your enemies, etc. It's not a demanding religion. It's easy. Their god doesn't care about charity or peace that take effort and compassion, but only that you are on His team.