Very few adult Americans are so ignorant that they mispronounce the word “corpsman.” Such a person cannot write a book that would get published, unless he self-publishes it. One can only shudder to realize this lamebrain is commander in chief.
I disagree.
I would even bet that about 47% of the population, if they saw that word, would pronounce it the same as Obama did.
Many of them are the same people who when they see the word "ASK", pronounce it as "AXE".
I would further venture that the average High School Graduate would not pronounce it properly, and if you pronounced the word and asked (sorry, AXED) them to spell it, they would spell it "COREMEN".
If you have some children, pronounce the word to them and ask them to spell it. You might be surprised by the answer you get.