Blumenthal served as assistant and senior advisor to Bill Clinton from August 1997 until January 2001.
His roles included advising the President on communications and public policy as well as serving as a liaison between the White House and former colleagues in the Washington press corps.

He later became a central figure in the grand jury investigation that ended in the impeachment of President Clinton.
While working for Clinton, Blumenthal was known for this loyalty to the Clintons and his attacks on their adversaries, which is one reason Rahm Emanuel, the first chief of staff for President Barack Obama, barred Blumenthal from holding a position in the State Department during Hillary Clinton's tenure as Secretary of State.

During his tenure working at the Clinton White House, Blumenthal was accused of serving as a "hatchet man" for the Clintons, often circulating rumors and false allegations about the Clinton's political adversaries: "Going back to the Bill Clinton impeachment crisis, Mr. Blumenthal, then the president's special adviser, spread false rumors that one of Kenneth Starr's prosecutors abused young boys at a Christian summer camp and that Monica Lewinsky was stalking the president," according to a November 2015 report by journalist Ken Silverstein appearing in The New York Observer.

"In 1995, Mr. Blumenthal told reporters that Alma Powell, Colin Powell's wife, suffered from clinical depression and was thus unfit to be a first lady.
At the time, there were rumors that Colin Powell would run in the Republican presidential primaries, a prospect that terrified the Clinton re-election campaign," The New York Observer further reported.

During the investigations by independent counsel Kenneth Starr, Blumenthal was called to the grand jury to testify on matters related to what Clinton had told both Blumenthal and his senior staff in regard to Monica Lewinsky.
The leadership of the Republican majority in the House of Representatives felt enough evidence existed in regard to the Paula Jones case and Lewinsky for impeachment proceedings to begin in December 1998.

After the House Judiciary Committee and the United States House of Representatives impeached Clinton on December 19, the matter then passed to the United States Senate.
Blumenthal was one of only four witnesses called to testify before the Senate.
No live witnesses were called; the four were interviewed on videotape.
His testimony addressed a major allegation that Clinton had pressured Betty Currie to falsely attest that it was Lewinsky who initially pursued Clinton, not vice versa.
The Senate acquitted Clinton of perjury and obstruction of justice, and the impeachment proceedings ended.
Blumenthal served as assistant and senior advisor to Bill Clinton from August 1997 until January 2001. His roles included advising the President on communications and public policy as well as serving as a liaison between the White House and former colleagues in the Washington press corps. 
He later became a central figure in the grand jury investigation that ended in the impeachment of President Clinton. While working for Clinton, Blumenthal was known for this loyalty to the Clintons and his attacks on their adversaries, which is one reason Rahm Emanuel, the first chief of staff for President Barack Obama, barred Blumenthal from holding a position in the State Department during Hillary Clinton's tenure as Secretary of State.
During his tenure working at the Clinton White House, Blumenthal was accused of serving as a "hatchet man" for the Clintons, often circulating rumors and false allegations about the Clinton's political adversaries: "Going back to the Bill Clinton impeachment crisis, Mr. Blumenthal, then the president's special adviser, spread false rumors that one of Kenneth Starr's prosecutors abused young boys at a Christian summer camp and that Monica Lewinsky was stalking the president," according to a November 2015 report by journalist Ken Silverstein appearing in The New York Observer.
"In 1995, Mr. Blumenthal told reporters that Alma Powell, Colin Powell's wife, suffered from clinical depression and was thus unfit to be a first lady. At the time, there were rumors that Colin Powell would run in the Republican presidential primaries, a prospect that terrified the Clinton re-election campaign," The New York Observer further reported.
During the investigations by independent counsel Kenneth Starr, Blumenthal was called to the grand jury to testify on matters related to what Clinton had told both Blumenthal and his senior staff in regard to Monica Lewinsky. The leadership of the Republican majority in the House of Representatives felt enough evidence existed in regard to the Paula Jones case and Lewinsky for impeachment proceedings to begin in December 1998. 
After the House Judiciary Committee and the United States House of Representatives impeached Clinton on December 19, the matter then passed to the United States Senate. Blumenthal was one of only four witnesses called to testify before the Senate. No live witnesses were called; the four were interviewed on videotape. His testimony addressed a major allegation that Clinton had pressured Betty Currie to falsely attest that it was Lewinsky who initially pursued Clinton, not vice versa. The Senate acquitted Clinton of perjury and obstruction of justice, and the impeachment proceedings ended.
Sidney Blumenthal