Prior to joining KKR, Mehlman spent a year as an attorney and partner at law firm Akin Gump Strauss Hauer & Feld.

[7][8] Mehlman received his undergraduate degree in 1988 from Franklin and Marshall College in Lancaster, Pennsylvania, where he became a member of Phi Kappa Tau's Xi chapter.

Mehlman practiced environmental law at Akin Gump Strauss Hauer & Feld in Washington, D.C. from 1991 to 1994, when he became legislative director to Representative Lamar S. Smith of Texas's 21st congressional district.

Mehlman served as Smith's legislative director from 1994 to 1996, and then as chief of staff to Representative Kay Granger of Texas's 12th congressional district from 1996 to 1999.

[12] In addition to his role at KKR, Mehlman is a trustee of New York's Mount Sinai Hospital, Franklin & Marshall College, and Teach for America.

Mehlman will chair the philanthropy's public policy advisory board, which he stated in his official Facebook post will consist of "a diverse group of advisors and experts.

[19] Mehlman was Bush's choice to replace Ed Gillespie as the chair of the Republican National Committee and was elected to the post on January 19, 2005.

[20] In his address to the NAACP on July 14, 2005, in Milwaukee, Wisconsin, Mehlman apologized for his party's failure to reach out to the black community in the aftermath of the Civil Rights Act of 1964, stating, "Some Republicans gave up on winning the African-American vote, looking the other way or trying to benefit politically from racial polarization...

A Washington Post poll shows that Bush's approval rating among African Americans fell to two percent at one point,[23] and a report card issued by the NAACP gave "F's" to a majority of Republicans in the 109th Congress.

[24] As the head of the RNC, Mehlman played a key role, along with Karl Rove, in executing the Republican Party's long-term, yet ultimately unsuccessful, plan for electoral dominance.

"[32] On November 8, 2006, comedian Bill Maher made an appearance on Larry King Live, during which he referred to Mehlman as a closeted gay man.

[4] A few commentators, such as Cenk Uygur and Michael Rogers, criticized Mehlman on The Ed Show, for having remained closeted about his sexuality while active in politics.

"[36] Gay & Lesbian Victory Fund President and CEO Chuck Wolfe said in a public statement, "We hope the fact that Ken Mehlman has reached this level of honesty will now encourage other political leaders to reject divisive anti-gay campaign tactics..."[37] In June 2011, Mehlman lobbied Republican members of the New York state legislature to support the legalization of same-sex marriage in New York and reached out to conservative donors and operatives.

"[45] In February 2013, Mehlman helped organize an amicus curiae brief to the Supreme Court in the case of California Proposition 8 signed by dozens of prominent socially moderate Republicans, including Jon Huntsman, Jr., Meg Whitman, Ken Duberstein, Ileana Ros-Lehtinen, and others, explaining that they supported a Constitutional right to same-sex marriage.

"We are trying to say to the court that we are judicial and political conservatives, and it is consistent with our values and philosophy for you to overturn Proposition 8," said Ken Mehlman according to the New York Times report.

[47] In November 2013, Mehlman launched a non-profit organization called Project Right Side [48] focused on convincing more Republicans to support marriage equality.

It is sufficient to recognize the inherent conservatism in citizens' desire to marry, to be judged on their work, and not to be singled out for higher taxes or bullying at school.

"[49] In February 2014, Mehlman was a keynote speaker[50] at the first campus-wide Harvard LGBTQ conference on the 45th anniversary of the Stonewall Riots where he was interviewed by Baruch Shemtov.

[52][53] In July 2019, Mehlman filed an amicus brief, joined by close to three dozen other Republican leaders, arguing in support of the rights of LGBT people in the workplace.

[55] In addition, Mehlman wrote an op-ed for The New York Times outlining his reasons for believing that the fight for gay rights upholds the Republican values of economic freedom and personal liberty.

In the piece, Mehlman writes that firing an employee because of their sexual orientation or gender identity is "... unethical and un-American, and the Supreme Court has the opportunity to read the clear language of Title VII [of the Civil Rights Act] and affirm that it is illegal.