I've never looked at grade or course devaluation as it may  relate to affirmative action.

Affirmative action permits less qualified to attend schools instead of those more qualified IMO, however.

Whether the professors dumb down the courses because of the students' lack of abilities or increase the scores to help either whites or minorities is a different issue and very difficult to quantify unless it is admitted by those involved. 

Looking at the number of 'valedictorians' in high schools today and the number of "A+++" students in colleges, grade devaluation does exist.

And if you have, as at the Duck U Law school, over 30% of their graduates who can't even pass the Oregon Bar Exam,  something is not being done correctly at that law school!  

And 25% can't find a job!

And it has few minorities. Out of 366 students, half are male, half are female.

And 281 are white.

18% minority.  Mostly Hispanics and Asian. 

 
http://law-schools.startclass.com/l/124/University-of-Oregon