You’ll have to check with Rupert Murdoch and Laura Ingraham first.
Don’t forget Ted Cruz and Jeb Bush, who have also proposed that the U.S. should accept only Christian refugees from war-torn Iraq and Syria. The trouble is figuring out who is Christian and who is not. Surely those who suspect terrorists of attempting to infiltrate the U.S. border with fake refugee status wouldn’t put lying past them. This would seem to bar a traditional profession of faith as a strong enough metric for determining one’s Christian-ness.
Further complicating matters are the historical schisms and attendant accusations of heresy that mark the history of Christianity writ large. Not only do the most dominant churches of Syria—the Orthodox Church of Antioch, the Melkite Greek Catholic Church, and the Syriac Orthodox—have liturgical and theological differences with churches commonly found in the West, they also tend to look and conceive of themselves differently than the average single-steeple box frame white Baptist church on the corner. Syrian churches may use different Bibles than most Western churches; may disagree on infant communion; and take different stances on Christ’s fundamental nature. If this all sounds like nitpicking, remember that people have died over such things.
To produce a test of Christian-ness, one would first need to come up with what it means to be a Christian, a task I doubt our esteemed media moguls and presidential hopefuls are up for. After all, nobody has come up with one that satisfies everybody yet.