Including a (then) sitting congressman: https://www.nbcnews.com/id/wbn...
The notion of an Islamic State would never be accepted
Afghanistan, Brunei, Iran, Mauritania, Oman, Pakistan, Saudi Arabia, and Yemen just asked "What about us?"
Right, you did say ethnicity, and not religion (which ethnicity is 'Islamic'?)... and admittedly it is a bit tricker because Jewish is often an ethnic group and religion, while much of the Islamic world, complete with state religions have countries more based on a dominant ethnic group going back some time.
Heck, with Somaliland in the news this week (and it's recognition by Isreal), it's flag contains the Shahada, which is also on the Saudi flag.
"More software projects have gone awry for lack of calendar time than for all other causes combined." -- Fred Brooks, Jr., _The Mythical Man Month_