Mixner suffered from complications from long Covid, a friend, Steven Guy, told The New York Times.
His legacy endures in the change he made and the generations of leaders he mentored and inspired.
I will miss him.

David Mixner in 2016Photo by Jared Siskin/Patrick McMullan via Getty Images
He was on and off crutches for the next several years, he wrote.
Known as the Briggs Initiative, the measure initially had overwhelming support.
Right up front he said, Look, I am probably going to endorse this initiative, he recalled.

David Mixner, Bill Clinton at Beverly Hilton Hotel, Los Angeles, 1999Getty Images
And then we had a long conversation and he was open to change.
And then he listened to our case and he changed his mind.
Reagans public opposition made a huge difference.
Public opinion shifted, and the measure was defeated.
The Dukakis fund-raiser, though, turned it down.
Too risky, the campaign official told him, according to Mixners memoir.
But Clinton was quickly met with opposition to lifting the ban.
Mixner went public with his opposition, and even was arrested during a protest outside of the White House.
For a time, his break with Clinton got him frozen out of the White House.
But that is OK, because I had to do what I thought was right.
Mixner and Clinton eventually reconciled.
In 2009, Mixner called for a march and rally at the Capitol.
I am a gay man, and I am free.
Contributions can be made to theDavid Mixner Memorial Fundto benefit the Ali Forney Center.