I question whether Trump has the legitimate legal authority to decide the taxable status of specific institutions. If he wants to change the rules about what qualifies for tax-exempt status, that takes an act of Congress (which he can probably get, eventually).<p>What he <i>can</i> do is tell the IRS to go through the <i>existing</i> rules and find a reason why Harvard doesn't qualify for tax-exempt status. The problems will be that, first, whatever the reason given will be, it will head for a court case, and second, it will be almost impossible to interpret the rules so that the new interpretation hits Harvard <i>only</i> (and not, say, the other Ivy League schools).