2016 Postmortem

Congress is really the only recourse against a President who violates the Constitution. And their only remedy is impeachment and conviction of a sitting President.

The Constitution is not made up of laws. It is a framework around which laws are created. The only criminal law in the Constitution regards Treason. Anyone attempting to file a lawsuit in federal court against the President will quickly discover that they do not have standing to do so. The Congress is the only body that has jurisdiction over the President and their method of operation is clearly defined by the Constitution when it comes to removing a President.

If Trump violates the Emoluments Clause, it will be up to us to convince the House of Representatives that he should be impeached. If we cannot do that, then he will be free to violate it as he chooses. Although he is forbidden to take payments from foreign governments, etc., no penalties for doing that are included in the clause. Lacking penalties, other than impeachment and conviction, there's nothing for anyone else but Congress to do to stop him.

Here's a reference link:

https://www.reference.com/government-politics/can-private-citizen-sue-president-2f8565a8eca32f83