Question: Cheryl Mills came into public prominence while serving as deputy to White House Counsel for which President ?
Context: Fred Fisher Fielding (born March 21, 1939) is an American lawyer.  He held the office of White House Counsel for US Presidents Ronald Reagan and George W. Bush in addition to serving as an Associate and Deputy White House Counsel for Richard Nixon under John Dean.  Fielding was also of counsel to the presidential transition of Donald Trump. Avril Danica Haines (born August 29, 1969) was the first female White House Deputy National Security Advisor, serving in Barack Obama's administration.  She previously served as Deputy Director of the Central Intelligence Agency, the first woman to hold this position.  Prior to her appointment to the CIA, she served as Deputy Counsel to the President for National Security Affairs in the Office of White House Counsel. Gregory Bestor "Greg" Craig (born March 4, 1945) is an American lawyer and former White House Counsel under President Barack Obama from 2009 to 2010.  A former attorney at the Washington, D.C. law firm of Williams & Connolly, Craig has represented numerous high-profile clients.  Prior to becoming White House Counsel, Craig served as assistant to the President and special counsel in the White House of President Bill Clinton, where he directed the team defending Clinton against impeachment.  Craig also served as a senior advisor to Senator Edward Kennedy and Secretary of State Madeleine Albright. Cheryl D. Mills (born 1965) is an American lawyer and corporate executive.  She first came into public prominence while serving as deputy White House Counsel for President Bill Clinton, whom she defended during his 1999 impeachment trial.  She has worked for New York University as Senior Vice President, served as Senior Adviser and Counsel for Hillary Clinton's 2008 presidential campaign, and is considered a member of Hillary Clinton's group of core advisers, self-designated as "Hillaryland".  She served as Counselor and Chief of Staff to Hillary Clinton during her whole tenure as United States Secretary of State.  After leaving the State Department in January, 2013, she founded BlackIvy Group, which builds businesses in Africa. Kathryn "Kathy" Ruemmler (born April 19, 1971) is an attorney who formerly served as White House Counsel to President Barack Obama.  She previously worked as Principal Deputy White House Counsel. Eric Schultz is a senior advisor to former President Barack Obama and is the founder of Schultz Group.  Schultz is a former White House Principal Deputy Press Secretary and special assistant to President Obama.  Recognized by "Politico" as the strategist “White House officials turn to in a crisis to handle communications,” Schultz was originally hired at the White House in 2011 to respond to Congressional oversight investigations.  After White House Deputy Press Secretary Josh Earnest replaced Jay Carney to become White House Press Secretary, Schultz was appointed White House Deputy Press Secretary.  In this role, Schultz often diffuses "tensions with humor.  But he can be relentless in pushing his message in both public and private conversations.”  Former White House Communications Director Jen Psaki compared Schultz to fictional crisis manager Olivia Pope, "he's the person you want next to you in a foxhole when there's a crisis."  At the end of President Obama's second term, former White House Senior Advisor Valerie Jarrett said of Schultz, “We’ve all grown to rely on his wise counsel" and that the President "trusts his sound judgement." The White House Counsel is a staff appointee of the President of the United States whose role is to advise the President on all legal issues concerning the President and his Administration.  The current White House Counsel is Don McGahn. William K. Kelley served as Deputy Counsel to United States President George W. Bush.  He worked as a deputy to White House Counsel Harriet Miers prior to her departure from the White House, and Counsel Fred Fielding, who succeeded Miers. Hillaryland was the self-designated name of a group of core advisors to Hillary Clinton, when she was First Lady of the United States and again when, as United States Senator, she was one of the Democratic Party candidates for President in the 2008 U.S. election. Cassandra Quin Butts (August 10, 1965 – May 25, 2016) was an American lawyer, policy expert, and Deputy White House counsel.  On December 23, 2008, Butts was selected by President-elect Obama to serve as Deputy White House Counsel, focusing on domestic policy and ethics.  She was also on the advisory board for then-president-elect Barack Obama's presidential transition team.  She stepped down as Deputy White House Counsel in November 2009 and served as Senior Advisor in the Office of the Chief Executive Officer at the Millennium Challenge Corporation.  In February 2014, Obama nominated her to be the ambassador to the Bahamas, but by February 1, 2015, the Senate had not confirmed her to the post.  She was re-nominated to the position on February 5, 2015.
Answer: Bill Clinton