Impeachment and the Emoluments Clause

At Brookings, Norman Eisen, Richard Painter, and Laurence H. Tribe have an brief titled "The Emoluments Clause: Its text, meaning, and application to Donald J. Trump."

While the phrasing may strike us as peculiar, everything about the Emoluments
Clause militates in favor of giving the broadest possible construction to the payments it
encompasses. For that reason, the Clause unquestionably reaches any situation in which a federal officeholder receives money, items of value, or services from a foreign state.

Just as plainly, the Emoluments Clause covers any transaction between a federal
officeholder and a foreign state in which the foreign state offers a “sweetheart deal” or any other benefit inconsistent with a purely fair market exchange in an arms-length transaction not specially tailored to benefit the holder of an Office under the United States.

... 

[If] Mr. Trump enters office in what would obviously constitute a knowing and indeed intentional violation of the Emoluments Clause and then declines to cure that violation during his tenure, Congress would be well within its rights to impeach him for engaging in “high crimes and misdemeanors.” This would not require any evidence of provable bribes or other specific malfeasance, since the whole aim and theory of the Emoluments Clause is that the President (among others) is not lawfully permitted to order his private dealings with foreign powers such that they are vulnerable to systemic, invidious, undetectable corruption. So long as Mr. Trump persists in doing so, Congress would have a plainly valid basis under the Constitution for concluding he cannot serve in office—both as a matter of first principles and given evidence that at least one prominent leader in the ratification process saw violations of this Clause as grounds for impeachment.