Kagan Colleague refers to two Supreme Court Justices, Samuel Alito and Antonin Scalia. Alito was appointed to the Supreme Court in 2006 by President George W. Bush and has served since then. Scalia was appointed to the Supreme Court in 1986 by President Ronald Reagan and served until his death in 2016. Both Alito and Scalia are considered conservative justices and were colleagues of Justice Elena Kagan, who was appointed to the Supreme Court in 2010 by President Barack Obama.