It is illegal for a President of the United States to sell influence, as such actions directly violate the U.S. Constitution's Emoluments Clauses, which prohibit accepting money, gifts, or benefits from foreign or domestic governments. Specifically, the Foreign Emoluments Clause (Article I, Section 9, Clause 8) and Domestic Emoluments Clause (Article II, Section 1, Clause 7) are designed to prevent corruption and undue influence.

Key legal and constitutional points include:

Bribery Laws: Federal law (18 U.S.C. 201) prohibits anyone from giving or offering "anything of value" to a public official in exchange for influence over an official act.

Foreign Influence: The Constitution restricts receiving "any present, emolument, office, or title" from a foreign state without Congressional consent.

Domestic Influence: The President is barred from receiving any profit, gain, or advantage from the federal government or individual states beyond their salary.

Ethics Regulations: While presidents are exempt from many ethics rules, using public office for private gain or to promote products is generally prohibited.

While presidents are not required to divest from personal business interests, they are subject to anti-corruption statutes and constitutional limitations that prohibit using their position for profit.