Michael D'Antonio is the author of the book "Never Enough: Donald Trump and the Pursuit of Success" and co-author with Peter Eisner of "The Shadow President: The Truth About Mike Pence." The opinions expressed in this commentary are those of the author. View more opinion articles on CNN.

(CNN) How much has the government spent protecting President Donald Trump and his family on vacations, business travel and golf outings? Nobody knows for sure -- because Treasury Secretary Steven Mnuchin is fighting requests to disclose the costs until after the 2020 election. What we do know is that the Secret Service has spent $588,000 renting golf carts since 2017.

Michael D'Antonio

No one would deny a president rest and recreation. However, it's also fair to consider this public servant's work/play balance, and ask how much we, as taxpayers, pay for him to have his fun and to keep him safe while he's doing it. For a president who says his is the "most transparent" administration in history, this picture sure is cloudy.

And then there's the hypocrisy of his golf habit. Trump repeatedly bashed his predecessor's penchant for the links, claiming he would take a different approach as President. On October 2014, Trump tweeted, "Can you believe that, with all of the problems and difficulties facing the US, President Barack Obama spent the day playing golf." In July 2015, Trump said , "I would rarely leave the White House because there's so much work to be done. I would not be a president who took vacations. I would not be a president that takes time off."

Flash forward three years and Donald Trump has spent at least 252 days at a Trump golf club, and 333 days at a Trump property since inauguration, according to CNN's count at the end of 2019. At this rate, Trump is on track to exceed Obama's record.

Trump's golf habit is also an example of the kind of self-dealing that is unprecedented among US presidents. Trump plays almost exclusively on courses that he owns. Thanks to this arrangement, the federal government, which he runs, pays the golf course corporations that he owns, for all the goods and services required every time he tees off. In the first five months of his presidency, the Secret Service paid more than $250,000 to President Trump's private businesses, according to the Washington Post , which cited records obtained by the nonprofit organization Property of the People

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