Name the five US presidents who did not officially affiliate themselves with the Protestant branch of Christianity.
Two of the presidents without a religious affiliation did not publicly identify as Christian; the other did but not as a member of any specific denomination
For the sake of this quiz, Unitarians and Quakers are considered Protestant
Christian sects that grew out of the Protestant Reformation are usually counted as Protestant. This does not include, for example, Eastern/Greek/Russian/Armenian/Ethiopian Orthodox, Lebanese Maronites, Egyptian Copts, etc... nor does it generally include Mormons, Quakers, Jehovah's Witnesses, Branch Davidians, Christian Scientists, the Moonies, Heaven's Gate cultists, or Muslims, etc, all of which are off-shoots of Christianity. Many Christian religious traditions which are not Catholic, particularly in Western Europe and North America, which began long after the Reformation of the 16th Century but nonetheless adhere pretty closely to Protestant beliefs, might be considered Protestant. But it's really all pretty arbitrary as religious belief and practice is constantly evolving and who's to say what constitutes a cult or new religion and what is simply a new church or custom within an existing religious framework...
... but for sure some non-Catholic Christians like the Armenian Orthodox church predates Martin Luther and Protestantism by centuries, and thus it would be very odd to call them Protestants.
Kinda building off what Kal said, I feel like Hoover and Nixon should be added since they were both Quakers. And for Jefferson, you might want to say "Deist"--I know it's not a Christian denomination, but it's the most accurate word to describe his beliefs.
(On an interesting side note, Jefferson made a unique version of the Bible where he cut out references to Jesus's divinity or miracles. If you want to read more about it, check this out.)
Thanks, all. Yes, the impetus for my question was that I know Nixon was a Quaker, which I do not really think of as a Protestant denomination. I was surprised he was not listed among the answers.
(On an interesting side note, Jefferson made a unique version of the Bible where he cut out references to Jesus's divinity or miracles. If you want to read more about it, check this out.)