David Cohen, a former president of the advocacy organization Common Cause, who for more than four decades campaigned for greater government transparency and accountability as a leader in the corps of activists known as public-interest lobbyists, died Nov. 29 at his son's home in Westport, Conn. He was 79.
The cause was a heart attack, said his son, Aaron.
"I have never heard a parent say, 'I want my child to be a lobbyist,'" Cohen once quipped, reflecting on the dim view commonly held of Washington insiders who use their savvy or clout to push their clients' interests among policymakers.
But Cohen saw himself and his colleagues not as representatives of special...