Janet Napolitano
Janet Napolitano is an American politician who served as Governor of Arizona from 2003 to 2009. She also served the administration of Barack Obama as the US Secretary of Homeland Security. After resigning as secretary in 2013, she also worked as the University of California’s president.
Napolitano was ranked ninth most powerful woman by Forbes in 2012 and was even touted by The New York Times as one of the women most likely to sit as the first female US president. Despite (or perhaps because of) her thriving career, she remains single.