For what reasons might a Justice leave the US Supreme Court?

Although US Supreme Court Justices are entitled to serve for life, and many do remain on the court until death, there are a variety of reasons a Justice may choose to leave, such as poor health, a desire to spend more time with family, frustration with the government or the political leaning of the Court, and so on.

A Justice may also leave if he or she is impeached by the House and convicted by the Senate for "Treason, Bribery, or otherHigh Crimes and Misdemeanors." (US Constitution, Article II, Section 4). Contrary to popular belief, a Supreme Court Justice cannot be impeached simply because an individual or group disapproves of his or her political beliefs.

The House of Representatives impeached Samuel Chase in 1804 because they didn't like his Federalist leanings, but the Senate acquitted him in 1805, establishing the right of the judiciary to independent opinion.