Sonia Sotomayor says Americans may not know difference between presidents and kings

Supreme court justice warns poor quality of civics education may lead to lack of understanding

The most senior liberal justice on the US supreme court has questioned whether American citizens know the difference between presidents and kings.

During a conference on civics education in New York on Tuesday, Justice Sonia Sotomayor warned that the poor quality of civics education means Americans may not be entirely clear on what makes a president different to a monarch.