Ann O’Leary, Gov. Gavin Newsom’s chief of staff, is a lawyer and an influential Democratic policy adviser. She started as a volunteer in Bill Clinton’s administration and became a senior policy adviser. During Hillary Clinton’s tenure as a U.S. senator, O’Leary was a legislative director and Senate aide. O’Leary was among Clinton’s three senior policy advisers when she ran for president in 2016; O’Leary also served as co-executive director for the Clinton-Kaine transition team. She has been a senior fellow at the Center for American Progress. Politico Magazine named O’Leary to its list of “thinkers, doers and visionaries transforming American politics” in 2015 and 2016.