After serving 5 ½ years as Attorney General, Eric Holder will formally announce his resignation later today at the White House. In addition to being the first African American Attorney General in U.S. history, he ranks as the fourth-longest tenured AG in history and also one of the few remaining Cabinet members from the beginning of the Obama administration.

His successor will need to be confirmed, and this could take some time. So who will be chosen to replace him?

NPR is reporting that “sources say a leading candidate for that job is Solicitor General Don Verrilli, the administration’s top representative to the Supreme Court and a lawyer whose judgment and discretion are prized in both DOJ and the White House.” Verilli is currently the 46th Solicitor General of the United States. His official biography on the DOJ page states that:

Verrilli previously served as Deputy Counsel to President Obama and as an Associate Deputy Attorney General in the U.S. Department of Justice. Prior to his government service, he was a partner for many years in Jenner & Block, and co-chaired the firm’s Supreme Court practice. He handled numerous cases in the Supreme Court and the courts of appeals, including MGM Studios, Inc. v. Grokster, which established that companies building businesses based on the unauthorized distribution of copyrighted works can be liable for inducing infringement; and Wiggins v. Smith, which established principles governing the right to effective assistance of counsel at capital sentencing.

Verrilli maintained an active pro bono practice throughout his career in private practice, and received several awards for his efforts. He also taught First Amendment law as an adjunct professor at Georgetown University Law School from 1992 through 2008.

Verrilli received his undergraduate degree from Yale University and his J.D. from Columbia Law School, where he served as editor-in-chief of the Columbia Law Review. He served as a law clerk to the Honorable J. Skelly Wright of the United States Court of Appeals for the D.C. Circuit and to the Honorable William J. Brennan, Jr. of the United States Supreme Court.

Even assuming that the President taps Verilli to follow his old boss Holder, he may face an uphill battle from Senate Republicans. He is, after all, the man that NPR dubbed “the man behind the defense of Obama’s health law,” as having successfully argued the administration’s position for three days before the Supreme Court regarding the Patient Protection and Affordable Care Act.