He was a mentor to many black politicians, including Los Angeles County Supervisor Yvonne Brathwaite Burke, who was elected to the state Assembly in the late 1960s before becoming the first African American woman elected to Congress from California.
"He gave the first event for me in his house," said Burke, recalling the fundraiser that kicked off her first campaign. He was, she added, "a great speechwriter" who helped her with the nominating speeches she gave when Jerry Brown ran for president and when Walter Mondale and Sargent Shriver ran for vice president.
Tenner was a large man with a commanding and colorful style who contributed his formidable powers to a number of progressive causes. At a Beverly Hills fundraiser for the nuclear freeze movement some years ago, he made a lasting impression on Dr. Helen Caldicott, founder of Physicians for Social Responsibility.
"I gave my usual hard-hitting and emotional speech," Caldicott wrote in a 1997 memoir. "At the end, a retired Superior Court judge . . . named Jack Tenner got up and fixed the audience with a beady eye. Dark, short, stocky and intense, he said, 'I can see $30,000 in this room, and nobody is leaving until we have collected.' He then accosted each person individually and, by God, he got the money. I've never seen anything so provocative in my life, and the crowd loved it."