Actually ... the question is misleading or mis-stated.
Jimmy Carter did not HAVE to divest himself, as the "conflict of interest" rules for Presidents are far less than those for Congress or any other political office.
Many Presidents made choices regarding "conflicts of interest" that they were not legally obligated to.
Yet those choices do not set any precedent for current or future Presidents.
Given that any decision a President makes would have some impact on virtually every business in the US, it would be silly to demand a President (and his family) sell all their business interests + stocks + bonds. The best we can ask, is that they do not take a direct hand in running any business while in office.
I do not defend (or attack) Trump any more than I would any other President.
Until Congress passes more restrictive "conflict of interest" laws on the President, we are stuck with what we have.
No use blaming any President for complying with existing laws.
Even Constitutional Scholars can't agree whether the "Emoluments clause" is being violated.
It obviously prohibits receiving GIFTS from a foreign government ... but does it prohibit being paid for doing business? THAT is what they can't agree on. And the only way to settle the question would be for a federal court to decide.
It would be a very interesting case, with wide-ranging implications besides to Donald Trump.
How many government officials own stock in companies that trade with other nations? Since we are in a global economy, it's almost impossible not to. And what about US Treasury bonds - since those are bought by other nations to fund our debt, could we say the entire government is in violation of the clause?
Yep. VERY interesting questions, that will likely be debated long after Trump is no longer President. Unless the Supreme Court weighs in.