We cannot know the contents of Donald Trump’s soul, but its fair to say his personal behaviour doesn't point to deeply held Christian belief. And yet the evangelical Christian right is a key pillar of his support base. Could that change in November’s election? Stephen Sackur speaks to Rob Schenck, an influential evangelical pastor and long-time anti-abortion activist who broke with fellow social conservatives over gun control. Can Donald Trump still count on the loyalty of the religious right?