"It's just another example of his consistent efforts to exploit public office for private gain," ethics expert Steve Schooner told NBC News. "He's using his official office and the fact that people have to travel with him, meet him, and follow him to promote his commercial enterprise, in this case his privately owned club." "I can't think of anything like this that we've seen at anytime in the modern era," the George Washington Law School professor told NBC News. The Mar-a-Lago property is still owned by Trump, who placed his holdings in a trust overseen by his eldest son, Donald Trump Jr., and Trump Organization CFO Allen Weisselberg before assuming office, prompting Schooner to lament that the president "should have divested from his properties to begin with." Since Trump became president the cost of membership at Mar-a-Lago has doubled, with guests now paying $200,000 just to join. "This is a privately owned club that for all intents and purposes was just another golf property in Florida before, that almost now is something that Americans immediately recognize," Schooner continued. "Imagine what you would have to pay to get that kind of brand recognition. That's extraordinary."

President Donald Trump and his wife Melania Trump arrive on Air Force One at the Palm Beach International airport. Getty Images