I asked the Chair of our Party, "Will you please tell him the difference between IDEAL and IDEA?"
I no longer quiz or correct people about this peculiar usage; however, several years ago I did talk to a friend because she also says IDEAL for IDEA. She told me that her whole family says IDEAL. I asked, "Didn't any teacher ever tell you the difference?" She was confounded, and after my saying "IDEA", she would repeat after me, "IDEAL." I asked, "Do you know that they are two different words with two completely different meanings?" She stated that she cannot HEAR the difference.
I read that was the same problem--with people who say "AKS" or "AXE" for "ASK"--that they cannot HEAR the difference. HOW can this be? It is very difficult to believe how our Fayette County School System has failed its students.
In checking the Internet, I learned that the use of IDEAL in place of IDEA is mostly a problem in the North. Of course, people from Massachusetts say "IDEAR" rather than "IDEAL", but that is just regional dialect, rather than actually NOT knowing the difference between the two words.