As a federal organized crime prosecutor, I learned that the mafia uses a practice known as "kicking up" or "paying tribute" to the boss. Essentially, all members of a mafia family must make sure that some of their earnings end up in the boss' pocket. From the member's point of view, "kicking up" is a way to show respect, curry favor, and reinforce the hierarchical power structure. From the boss's point of view, it's a way to get rich.
The "kicking up" model works well for the mafia, and now a political version of it seems to be catching on within the Trump administration. Vice President Mike Pence has decided to stay at Trump's golf resort in Doonbeg, Ireland, during an official visit to Dublin (over a one-hour flight away, so not particularly close or convenient). On Tuesday, Pence's chief of staff remarked that the decision was made on Trump's suggestion. The Vice President's office later stated, "at no time did the President direct our office to stay at his Doonbeg resort."
Not to be outdone in the "posterior osculation" category (as Paul Begala colorfully put it), Attorney General William Barr reportedly will spend more than $30,000 of personal money to throw a private holiday party at the Trump International Hotel in Washington DC. Barr's defenders argue that he first tried to book two other DC hotels. But, of course, there are dozens of luxury hotels in DC that Barr could have chosen instead of one owned by Trump's company. Apologists can nibble at the margins, but there is no escaping that Barr's choice to patronize a Trump property, like Pence's, will put thousands of dollars in Trump's pocket.