[3] Following his undergraduate degree in social studies, Sander became involved with the federal Vista program working with a housing group on the south side of Chicago.
During his graduate studies at Northwestern, Sander served on the board of the Rogers Park Tenants Committee and was involved in the election effort of Harold Washington, Chicago's first black mayor.
[6] Sander is known for his research on affirmative action, which claims that it actually causes more negatives than benefits for African American law students by hurting them due to the overly competitive environments in more prestigious schools, through what he calls the "mismatch effect".
He published his research in a 2004 article in Stanford Law Review where he claimed that if minority students had been admitted into less-competitive schools for which they would qualify without affirmative action, they would have been more successful.
[14][15][16] In 2015, Sander filed a Brief Amicus Curiae In Support of Neither Party in regards to the affirmative action issue addressed by Supreme Court of the United States in Fisher v. University of Texas.
[18] Sander has also co-written a book, along with Stuart Taylor, Jr., entitled Mismatch: How Affirmative Action Hurts Students It's Intended to Help, and Why Universities Won't Admit It.