A President must swear to support the Constitution against all enemies foreign and domestic. Carson claims a Muslim would not be able to do that because of his duty to support the command of Islam to convert or kill non-believers. The animosity between Muslims and America has been going on since America was founded. In 1801, President Thomas Jefferson fought the Barbary Pirates who were Muslims. The Marines began with the battle of Tripoli against Muslims.
The differences between the Muslims beliefs and the Constitution are stark, well-known and have been documented since before the American Revolutionary War.
(See: The Barbary Wars: American Independence in the Atlantic World, by Frank Lambert (2005); Jefferson’s War: America’s First War on Terror 1801–1805, by Joseph Wheelan (2003); To the Shores of Tripoli: The Birth of the U.S. Navy and Marines, by A. B. C. Whipple (1991, republished 2001); and Victory in Tripoli: How America’s War with the Barbary Pirates Established the U.S. Navy and Shaped a Nation, by Joshua E. London (2005). Most recently, in his new general history, Power, Faith, and Fantasy: America in the Middle East, 1776 to the Present, the Israeli.)
Islam has been at war since it’s inception. America is not a warring nation although America has fought and won wars. Dr. Ben Carson is correct about the impossibility of a Muslim taking an oath to put the Constitution and America above everything. It’s just a set of facts that validate his words.
Carson is not against Muslims. He seems to understand them more than the average person. Is he wrong? Perhaps. Muslim officials in America have responded with some ideas of their own but they haven’t denied his conclusion about the Presidential oath.