'Breaking the War Mentality' by Barack Obama (1983)
The essay, which appeared in Sundial while Obama was attending Columbia University, certainly does not evince any of the writing flair shown in Obama's much-lauded, bestselling books, Dreams of My Father and The Audacity of Hope.
Over at News Real Blog, Matthew Vadum has written a scathing review of Obama's essay and concludes his review as as follows:
If you’re having trouble getting to sleep one night, I recommend you read the article.
You’ll be out before you finish the first page.
Anyway, if you want to read what seems to be actual writing by Obama during his college years, the first link in this post leads to that rarity.