Hispanics are the fastest-growing evangelical group in the country right now, an important constituency. But Trump's views, especially his views on immigration, did not exactly go over well with this faith constituency. Rev. Rodriguez told me that Trump's invitation created something of a stir in his world.

When ISIS last year called for the destruction of the Yazidi people, President Obama said that would constitute genocide and he ordered U.S. forces to keep it from happening. Human rights advocates say Christians now face a similar threat Nina Shea directs the Center for Religious Freedom at the Hudson Institute.

Many immigrant groups have faced hostility. The Irish did in their time. Jews did. Italians did - and now, Muslim immigrants.

A similar move is underway in the British Parliament. Earlier this month, more than 30 religious leaders and scholars wrote Secretary of State John Kerry asking for a meeting to discuss what's happening to Christians and other minorities. Nina Shea organized the effort.

Trump has always talked about how important in dealing with foreign leaders, how important it is to establish a good personal relationship very close to what Pope Francis says, so they may both really want to emphasize their development of a personal relationship.

If you're wealthy like Donald Trump is, and you have a preacher who says your wealth is a sign God approves of you, you're probably going to like that preacher. And if there is one major element in Donald Trump's religious beliefs, it would be this prosperity gospel.

ISIS goes after any group that deviates from its extreme ideology, dissident Muslims, for example, or the Yazidis who practice an ancient religion distinct from both Islam and Christianity.