http://www.gallup.com/poll/165626/death-penalty-support-lowe...
I don't know what it is, but Americans - especially the Bible Belt voting bloc (for lack of more nuanced regional targeting) - feel not only "just" in passing judgement on others, but divinely so, and therefore questioning them is questioning God. It's scary. (It's also the same voting bloc backing Trump. We could chat all day about misappropriated rage and the decline of financial stability and the middle class, but the result of decades of it is where we are now.)