Cherny was born in Los Angeles, California on August 4, 1975. His parents, Helena (née Weltman) and Pavel Cherny, were Czechoslovakian Jewish immigrants that spoke little English.
Cherny graduated with honors from Harvard College. He later received his Juris Doctor from the University of California, Berkeley School of Law (Boalt Hall) with support from The Paul & Daisy Soros Fellowships for New Americans.
As a writer for The Harvard Crimson, he wrote political pieces highlighting Clinton's reelection campaign. The White House communications director noticed his column and circulated it until it finally reached President Clinton's desk. President Clinton used several of Cherny's lines in his 1997 inaugural address and hired the twenty-one-year-old Cherny ten days later. Cherny was the youngest White House speechwriter in American history. President Clinton has called him a “critical part of the team” which brought about the economic successes of the 1990s.
Cherny then went on to be an advisor to elected officials and business leaders. Over the years, he has provided policy and strategic advice to Barack Obama, Joe Biden, Bill Clinton, Al Gore, Hillary Clinton, John Kerry, the top executives of companies such as Microsoft and Intel, and prominent civic leaders.
Cherny is the co-founder and President of Democracy, a public policy journal and think tank that seeks to spur new ideas on the major issues facing America and the world. Democracy’s ideas, such as the Consumer Financial Protection Bureau at the heart of the 2010 Wall Street reform, have made their way into the national political debate and into legislation in Congress and states across America. Today, Democracy has 300,000 readers in every state and more than 150 countries around the world.
He was the chief drafter and lead negotiator of the 2000 Democratic Party platform when Al Gore was the nominee for president.
In 2003-04, he was the Director of Speechwriting and Special Advisor on Policy for John Kerry's campaign for president. He was credited with the new strategy that revised Kerry's faltering primary candidacy and helped win him the Democratic nomination.
Cherny was a Visiting Fellow at Harvard University's Belfer Center for Science and International Affairs at the Kennedy School of Government in 2004. In 2011, he was a Senior Fellow at the Center for American Progress.
He served from 2006-09 as a criminal prosecutor and Arizona Assistant Attorney General. He amassed a 100% conviction rate prosecuting corporate crime and financial fraud.
He is also the author of The Next Deal: The Future of Public Life in the Information Age, and The Candy Bombers: The Untold Story of the Berlin Airlift and America's Finest Hour. "The Candy Bombers" was described as like “Stephen Ambrose at his best” by historian Douglas Brinkley and “everything one could want from a work of history—engrossing, informative and stirring” by the Washington Post. Cherny’s first book, "The Next Deal: The Future of Public Life in the Information Age" examined how American government must change to meet the challenges of the 21st century New Economy. The Los Angeles Times called the book “visionary in scope,” the Financial Times reported that The Next Deal “has become required reading” in British Prime Minister Tony Blair’s office.
Cherny served as Chairman of the Arizona Democratic Party from January 22, 2011 through January 30, 2012.
In 2012, Cherny lost the Democratic primary for Arizona's 9th congressional district.
In 2010, Cherny was the Democratic Party nominee for Arizona State Treasurer. He lost the election to Republican Doug Ducey, receiving 41% of the vote in a four-way race. His campaign raised over $1 million. Cherny ended the campaign by traveling to all fifteen counties in Arizona in a 24-hour period—likely the first person in history to do this.
At the age of 26, while a law student, Cherny ran for the California State Assembly and lost to Lloyd Levine.