Donald Trump's latest campaign target isn't another candidate, it's the Pope after the Pontiff questioned Trump's immigration policy.

FOX's Jared Halpern has more:

Hours after praying at the the U.S. Mexico border, Pope Francis told reporters anyone who thinks only about building walls is not Christian, a response to a question about Donald Trump.

Trump, quick to respond, reading from a prepared statement in South Carolina:

(Trump) "No leader, especially a religious leader, should have the right to question another man's religion or faith."

Trump also warned the Pope that if and when ISIS attacks the Vatican, the Pope would pray for Donald Trump to be President.

All of this playing out just two days before the South Carolina primary, where the latest FOX News poll shows Trump is a far-and-away-frontrunner.

Jared Halpern, Fox News.