It's not just Trump.
Pretty much all of his supporters 'outed' themselves this year. If Trump loses the election, all of them are going to have to answer to their opposing friends and families for years.
They'll have to wrestle with the fact that they supported a man who has said and done terrible things, who is a terrible role model, who doesn't honor contracts, who is a misogynist pig, who may also be guilty of raping a 13 year old at a sex party years ago...
How can anyone live with themselves after that? Especially if he loses the election?
Company CEOs who support him are going to take a hit on their brands - even his own daughter is concerned about her father's scandalous background.
Trump is going to leave a lasting stigma on all of his supporters, win or lose. But MUCH more if he loses.