Politifact.com quotes Africa Center Director J. Peter Pham on the rumor that President Obama's acceptance of the King Abdul Aziz Order of Merit from Saudia Arabia in 2009 violates the US Constitution:
On the one hand, J. Peter Pham, director of the Atlantic Council’s Africa Center, said the King Abdul Aziz Order of Merit "is more than a mere medal. It confers an order, as indicated by its name, even if most people don’t take such things as seriously anymore."
When King Saud created the order in the 1950s, Pham said, it was "modeled after the various orders of chivalry awarded by European royal houses," such as the United Kingdom’s Most Honorable Order of the Bath and Spain’s Order of Isabella the Catholic.
Pham said these orders, both Saudi and European, "are differentiated from medals awarded for military service or civilian achievement. The latter are properly decorations, while the former confer membership, or honorary membership, in a class of individuals which, in former days, would have been referred to as having raised the recipient to the nobility if he or she did not already belong to it."
In a 2009 Washington Post op-ed, Pham and Chapman University law professor Ronald Rotunda argued that "Washington, Madison and Hamilton would have clearly understood that the Abdul Aziz Order falls under the same ban they had in mind for any public officials coveting awards made under the honors system of the British monarchy."