Lots of folks out there are speculating why Donald Trump won't release his taxes. What the heck is in them that he doesn't want anyone to see?
I would like to speculate that there may not be a specific thing he's hiding. He knows that the minute he makes them public, opposition research is going to go to work, scrutinizing every last item and trying to see if there's any way they can spin it as a negative for him. He knows this because that's what everyone does, what his forces do with every bit of information they can get about Hillary Clinton.
During the Impeachment of Bill, that was a lot of what was going on. Under the guise of investigating and demanding "transparency," a lot of Bill's enemies were saying, in effect, "Let us dig deeper into your files in search of stuff we can use against you! Maybe we can find an actual crime in there…and even if we can't, there's probably something we can make sound like a crime!" So it may just be that Trump doesn't want to make it easy for them to do that.
Then again, if this article is true, the thing Trump fears most is people believing he's not as rich as he claims to be. You can make fun of his hair, his failed marriages, his failed businesses, his weight…you can even say he yearns to bang one of his daughters. But don't you dare say he's not fabulously wealthy. So maybe it's that.