U.S. Supreme Court Justice John Paul Stevens has announced he will retire, leaving President Obama with the task of appointing a second justice to the High Court.

During his 35 years as a Supreme Court Justice, Stevens has been the leader of the court's liberal wing. He has weighed in on court decisions ranging from how to try terror suspects at Guantanamo Bay to the application of the death penalty, and legal scholars say he will be remembered for his polite demeanor and consensus-building abilities.

President Obama's appointment task will not be easy, since he must find a candidate to replace Stevens who can survive the Senate confirmation process. Senate Republicans are expected to oppose any nominee who is too liberal, but the president will likely seek a replacement who can maintain the court's current ideological balance.

"He has stood as an impartial guardian of the law. He has worn the judicial robe with honor and humility. He has applied the Constitution and the laws of the land with fidelity and restraint." - President Barack Obama

"This is the end of one of the great tenures on the court. Justice Stevens served 35 years through seven presidents and three chief justices. And he's become really the liberal leader of the court, a statesman who perhaps moved left as the court moved right." - Kathleen Sullivan, Constitutional Law Professor, Stanford University

"Well, I think, first, as a person, if you only knew him from watching him on the bench, you would see somebody who is unfailingly polite, even to the point of apologizing when he interrupts a lawyer's statement to ask him a question, someone who asks very direct questions, no agenda, incredibly smart hypotheticals that can find a lawyer's weakness in his argument very quickly, and very modest person." - Marcia Coyle, The National Law Journal

1. What is the Supreme Court? How many justices serve on the court?

2. How long do Supreme Court justices serve?

3. Who chooses a new Supreme Court justice? Who must approve the choice?

1. Why could nominating a justice to replace Justice Stevens be a tricky task for President Obama?

2. According to the video, what were some of Justice Stevens's landmark decisions during his time on the Supreme Court?

3. Why is the retirement of a Supreme Court justice so significant? In general, what kind of consequences could it have for the country?