What did Donald Trump do today?

He promoted one of his golf courses on the taxpayer dime.

Trump golfs almost every weekend, and taxpayers pick up the tab to the tune of at least $4 million for each trip—a figure that doesn't include the cost to local law enforcement, unreimbursed disruption to businesses, and other expenses. And Trump, who stays exclusively at his own properties and forces government employees, including his Secret Service detail, do the same, makes money on each trip.

Trump's golfing this week has been taking place in Scotland, home to two golf courses he owns—and, as of a ribbon-cutting today, a third. The cost to American taxpayers for Trump to promote his new course is estimated to be at least $10 million.

Trump's personal wealth comes from a variety of sources: a nearly half-billion dollar inheritance carefully and illegally hidden from the IRS (including a suspicious last-minute attempt change to his dementia-suffering father's will to benefit himself), tax write-offs from investment "losses" in the casinos he bankrupted that actually came out of the pockets of other investors, and any number of penny-ante product hustles, ranging from a to cheap Trump-branded collectible sneakers. Lately, on paper at least, much of his money comes from cryptocurrency "tokens" that can be used as ways to untraceably put money in Trump's pocket in exchange for whatever goodwill that might get the buyer—like, for example, Trump ordering the SEC to drop civil fraud charges against his biggest buyer.

But the durable value of Trump's real estate holdings are still important to Trump, if only because they represent the business he's found it hardest to lose money in. Property tends to hold its value over the long term no matter who owns it, and for people—or countries—looking to buy Trump's attention without buying fake digital coins, real estate "investments" or simply overpriced club memberships are a straightforward way of doing it.

Officially, the purpose of the trip was to sign a trade agreement with the European Union—even though the golf course opening has been planned for years, and Trump's global trade war has only been going on since he returned to office. But even that excuse doesn't appear to be holding water: the deal Trump announced, and the one the EU says was actually negotiated, are two totally different things. 

This is not the first time that's happened in recent weeks with Trump's hastily announced "deals."

Why does this matter?

• Anyone who needs to be president to make money in business is terrible at both jobs.