A number of years ago I interviewed an old journalist who'd met every Arizona governor except the first one. (Arizona became a state in 1912 and the first governor was in office a long time so it wasn't impossible.) He'd covered a lot of political campaigns and had colorful and candid opinions about the local politicians.
One day over lunch, he remarked that he'd learned one thing in his career: "Today's S.O.B. is tomorrow's hero."
I often remember that observation and relate it to executives and managers who've had career setbacks. Most people are very forgiving and the avalanche of news rapidly transforms hot headlines into ancient history. Add to that the fact that come-back stories are popular and there is increased potential for a rebound.
Americans, often to their detriment, don't pay that much attention to the past. We tend to focus on the Now and the Future. "What have you done lately?" is the relevant question. Barring something horrendous, it can be relatively easy to become known for your better, and more recent, deeds.
The secret is to give people a reason to forgive and then let time do its work.