Who is the current Chief Justice of the United States?

John Roberts serves as the current Chief Justice of the United States. His role as Chief Justice is crucial as he presides over the Supreme Court, leading its deliberations and ensuring that the judicial process is upheld. Appointed by President George W. Bush in 2005, Roberts has played a significant role in important cases that shape national law and upholds the Constitution.

The other individuals mentioned have had (or had) notable roles on the Supreme Court. Ruth Bader Ginsburg, who passed away in September 2020, was known for her advocacy of gender equality and civil rights. Clarence Thomas is an Associate Justice and has been a member of the Court since 1991, recognized for his conservative judicial philosophy. Elena Kagan, also an Associate Justice, was appointed in 2010 and is known for her progressive views. However, none of them hold the position of Chief Justice, which is why Roberts is the correct answer.