Democracy4Sale wrote: He has a three-year window to file an amended return and reclaim the rest of the deductions he didn't claim, (in order to manipulate his tax-rate). If he loses the election, the odds are virtually 100% that he will do so.
I already provided a quote and link quoting a U of Colorado law professor (Victor Fleischer) and others saying he can't reclaim that money. If you have a link that says different, I'll take a look at it.
Normally you can later file an amended return if you made a mistake. But in this case, for some reason, he declared the full $4 million (my link says $4.6 million) so I'm guessing that's why you can't later amend since the decision was already made (no error to correct).
Now, why would he declare the full amount? Normally you only declare the amount you want to deduct and there is no requirement to declare all charitable deductions. My guess (again) is it's because $2 million went to a family charitable trust. The trust probably has to report its contributions to the IRS, so in effect he's declared that $2 million.