Dawn Johnsen was nominated for the Office of Legal Counsel in January of 2009 but was finally forced to withdraw her nomination a few days ago. The Legal Counsel advises the President on matters of civil rights and adherence to the rule of law. She was an excellent choice for those who believe the rule of law trumps executive power.
In practice the Obama administration has stuck too closely to the Bush doctrine of executive power and having Johnsen in the picture could have made things quite uncomfortable.
The White House had the votes to for her nomination through but never pushed it.
The full story here, written by the always excellent Glenn Greenwald, a constitutional lawyer himself.