Karen Leaffer is a left-of-center nonprofit lawyer based in Denver, Colorado. She is the founder and managing partner of Leaffer Law Group, a specialized firm which provides legal counsel to nonprofit organizations. Leaffer is an active philanthropist and member of left-of-center donor networks, serving on the board of the Colorado Democracy Network.
Karen Leaffer is married to Steven Leaffer, President and Owner of O.L.P Management Company, a Denver-based property management company.  Steven Leaffer is also on the board of Judaism Your Way, and the couple is involved in philanthropy in the Jewish community through Judaism Your Way and the Rose Community Foundation. 
In 2005, Karen and Steven Leaffer gave a $300,000 donation to the Center for Women’s Health Research at the University of Colorado at Denver in honor of their daughter, Jacqueline, who died due to medical complications in infancy.  The couple has remained involved in the health community through their philanthropic efforts, with both Karen and Steven serving on the board of the Center for Women’s Health Research.
Leaffer attended Gonzaga University before receiving her law degree from the University of Idaho, followed by an LL.M from the University of Denver.  She has worked in Colorado for the past several decades, serving as partner at two of Denver’s largest law firms before opening her own firm, the Leaffer Law Group. 
For the past twenty-five years, Leaffer has worked as a nonprofit attorney. She is the founder and managing partner of the Leaffer Law Group. The firm handles legal work for nonprofits, specifically helping foundations with tax-exempt compliance, grant-making, gift management, and contract work. 
In addition to her legal career, Leaffer is directly involved with a variety of nonprofits. She serves on numerous nonprofit advisory boards, including the Advisory Committee on Business Entities for the Colorado Office of the Secretary of State, the Advisory Board of the University of Colorado Women’s Health Research Center, and the Space Science Institute.  Leaffer is also involved in advising the Rose Community Foundation, a left-of-center grantmaking foundation based in Denver. 
Leaffer’s highest profile nonprofit commitment is as a board member at the Colorado Democracy Network, also known as the Colorado Donor Alliance.  The Colorado Democracy Network is a convening of left-wing donors and foundations focused on pushing left-of-center policy in Colorado. It is closely affiliated with the Colorado Democracy Alliance, an organization founded in 2004 by Democratic mega-donors with the intent of turning Colorado into a consistently Democratic-leaning state in elections.
Leaffer has taken an active role in supporting left-of-center policy, even outside of her work as a nonprofit attorney and philanthropist. She has provided funds to the Trailhead Institute, a left-of-center public health organization whose main projects include promoting youth “sexuality training” and environmentalism.  
Over the years, Leaffer has made over sixty political contributions, all to left-of-center politicians and organizations.  Most of these contributions have been to female Democratic candidates, including a donation to Hillary Clinton’s PAC during her first attempt at securing the Democratic nomination for president in 2008.  More recently, she has donated to the presidential primary campaign of U.S. Senator Kirsten Gillibrand (D-NY). 
Leaffer has donated to several left-wing candidates, including $8000 in contributions to New York State Senator Julia Salazar (D-Brooklyn). Salazar is a self-proclaimed democratic socialist supported by the Democratic Socialists of America (DSA). 
Leaffer has supported left-wing candidates in Colorado as well, giving $4,500 to U.S. Rep. Diana DeGette (D-CO) in 2019 and $2800 to U.S. Rep. Joe Neguse (D-CO).  Leaffer has been a longtime supporter of the far-left DeGette, supporting her in Democratic primary races as well as in general elections.