To be tax-deductible to the donor, donations to charities have to be "gifts." If they have conditions that confer value back to the donor they are not gifts. Also gifts cannot be earmarked to be directed a specific beneficiary of the charity.
Also, charities have to be aware that they may be generating "unrelated business income" by accepting a donation in trade for something of value, as such income is taxable.
Sure, it's the letter of the law that donations have to be gifts. But nonprofit development (=fundraising) work has lots of gray areas.
A simple example: gifts may be restricted. Restricting a gift is as simple as writing a $10 check to the Sierra Club and writing "spotted owl conservation" on the memo line. If the Sierra Club doesn't have a spotted owl program, they're supposed to get your permission to apply the gift elsewhere.
If your gift were for half a million dollars and restricted that way, you'd be trying to set policy with it.
Not all attempts by donors to drive policy are harmful to the org. And, not all such attempts are self-dealing or other fiscal shenanigans. Usually they're far more banal clashes of egos.
I think the crazy way Donald Trump used his charity demonstrates that it is probably pretty easy to abuse charities in the US. I am not trying to make a political point, I'm sure there are liberals who take advantage of charities too. But if Trump wasn't running for President, would anyone have noticed how the funds were being used?
And likewise, the reason that Soon-Shiong's actions are under scrutiny is that his name has been mentioned as a possible director of the National Institutes of Health (although Obama's pick of Francis Collins is being kept on for the time being).
That kind of thing isn't usually above board, though, is it? If I give a charity a million dollars and then make a suggestion, the subtext is clear even though there aren't any official conditions.
Also, charities have to be aware that they may be generating "unrelated business income" by accepting a donation in trade for something of value, as such income is taxable.