From a newly released set of documents today from the Clinton library

I have spent much of the past week carefully reading Lani Guinier’s recent law review articles and other pertinent  materials. On this basis, I have reached a difficult conclusion: it is my duty to.recommend to you that her nomination to serve as Assistant Attorney General for Civil Rights be withdrawn. Irecognize Prof. Guinier’s academic accomplishments and considerable experience as a civil rights litigator. But the perspective she would bring to the Justice Department would ill
serve the interests of our country and your administration.

In particular, Prof. Guinier’s understanding of the Voting Rights Act–which she would have principal responsibility for interpreting and enforcing–is inconsistent with the intent of Congress and far outside the mainstream of judicial opinion. An effort to implement the Act as she understands it would lead to a morass of litigation and would undermine you longstanding effort to promote reconciliation across racial and ethnic lines.

You can also read Pres. Clinton’s handwritten changes to his announcement withdrawing her nomination.