If and when Chump releases his tax returns, neither his rabid supporters nor his detractors will change their minds about him.

What he's really scared of, is showing that he's not nearly as rich as he's bragged he is.

Being shown a blowhard liar is his biggest fear in life and is what drives his massive insecurity.

Which is ironic, given that he still probably has more money than he can spend in his lifetime.