I heard the president of Morehouse College say this on C-SPAN yesterday at Tavis Smiley’s “State of the Black Union 2008” conference in New Orleans.

Problem:
This is a mispronunciation of the correct word.

Explanation:
Although it’s true that one dictionary — Webster’s New Millennium Dictionary of English — contains this word, one has to realize that dictionaries not only are sources of what’s correct but also are references to incorrect forms.

For fun, I searched Google for “supremist” and “supremacist” (the correct word) and got about 84,700 and 1,280,000 matches, respectively. That tells me that Web authors have written the word correctly by a ratio of 15.1:1, which is good, but not excellent.

I believe that the use of “supremist” instead of “supremacist” is consistent with my “Devolution toward Simpler” hypothesis. The incorrect word has three syllables to the correct word’s four syllables, and it is simpler to pronounce the “ist” sound than to pronounce the “acist” sound.

Solution:
“Supremacist”