Carolyn Walker-Diallo is simply one of several American officials who has chosen to be sworn in on the Koran rather than the Christian Bible. Over the years, there have also been others who have decided not to use the Bible when swearing in, or taking their Oath of Office. And some of the choices to swear in even included using something other than a Koran.
The next most public instance of a government official choosing to swear in on the Koran was Keith Ellison. In 2007, he made his swearing in on the Koran quite public. It's supposed to be a private ceremony. So the fact that he chose to make it as national as he could and swore in on a Koran says something about his true allegiance.
Ellison was sworn in on a Quran that Thomas Jefferson owned. The reason Thomas Jefferson owned a Quran (or Koran) is because America was being terrorized by Muslim naval forces and Jefferson was trying to figure out what they believed so he could understand how to negotiate with them. What he and (at the time) President George Washington and many other government leaders learned, in a nutshell, is that you can't negotiate with terrorists. Why? Because what they ultimately want is to take over and implement and enforce their own rulership and belief system.
An American oath of office typically includes upholding the Declaration of Independence, Constitution and the Bill of Rights. John Brennan chose to be sworn into his position with the CIA on the Constitution alone in 2013. This sounds good at first glance until one digs a bit deeper and discovers that he had requested the original draft, which did not include the Bill of Rights, which means that none of the Amendments to the Constitution, such as freedom of speech, freedom of religion, states' rights or any of the other Amendments were included.
US Ambassador to Switzerland Suzy LeVine was sworn in on an electronic version of the Constitution. There was not a Bible or any other holy book included in her swearing in, so one might wonder to which god she was referring when she uttered the words, "So help me god," at the end of her oath -- if she invoked any god or believes in one at all at this point in her life.
It's interesting to consider Kim Davis' argument in light of all of this. Davis refused to issue marriage licenses in spite of her Oath of Office, because her interpretation of the words at the end of her oath, "So help me God," meant to her that she would uphold, "the federal and state constitutions and laws [so long as], she would not [be forced to] act in contradiction to the moral law of God."
There was quite a media frenzy about the fact that Davis was holding the Bible in a higher regard than America's governmental documents. And Davis was right to do so according to the teachings of true Christianity. It's interesting to consider what might have happened if Davis were a Muslim refusing to issue same-sex marriage licenses because it went against the Koran or the hadith. Would mainstream media still have demonized her? Islam actually commands that homosexuals must be executed.
If a Muslim is sworn in on the Koran, will that Muslim put sharia law over the laws of the US documents because he or she feels that they cannot act in contradiction to Allah? After all, a true Muslim believes that their holy book and the Hadith are what is in the best interest of society -- a Muslim society.
What if a Wiccan or even a Satanist became a government leader and wanted to be sworn in on the Satanic Bible? Just because it hasn't happened yet doesn't mean it can't happen.
Somewhere within all of the confusion of what holy book government leaders are going to be sworn in on, America needs to make a decision about what it wants its foundation to be. The way the Biblical prophet Elijah might word it can be found in 1 Kings 18:21: "How long will you falter between two opinions? If the Lord is God, follow Him; but if Baal, follow him."