Who holds the Supreme Court accountable?

The US supreme court starts a new term on Monday, and the nine justices are preparing to take on cases that could prove crucial to the future of American society and democracy. Jonathan Freedland speaks to Prof Leah Litman about what exactly motivates the nine judges who are supposedly tasked with upholding the US constitution? When did the highest court in the land become so apparently partisan? Is there any coming back from this?