There’s only one sure thing in politics: when the President tees off, someone’s going to get mad.

After playing one of his golf courses for the 14th time since his inauguration this past weekend — this time to discuss healthcare with Sen. Rand Paul — President Donald Trump is being sniped at for hitting the links. That’s nothing new. Trump himself blasted Barack Obama dozens of time for playing too many holes. Previously, George W. Bush was so heavily criticized for golfing during the Iraq War that he stopped.

By some estimates, 18 presidents have putted since William McKinley teed off. So, there’s surely reason why so many commanders-in-chief brave public disapproval. For one, playing the full 18 holes gives them four to five hours alone with select company. “The very nature of the game enables them to speak with other leaders in a much more relaxed situation,” says Tony Dear, author of “The Story of Golf in Fifty Holes.” “They will say things they wouldn’t in the Oval Office or boardroom.”

Two presidents. 18 holes. (Chris Kleponis-Pool/Getty Images)

Numerous diplomatic deals have their genesis at the links. When asked about the president’s golfing habits in March, White House press secretary Sean Spicer said that “how you use the game of golf is something that he’s talked about.” Indeed, the tactic has been endorsed by none other than the author of “The Art of the Deal,” whose namesake Trump Organization operates 17 golf courses (That said, the White House has been coy about whether Trump has actually played golf during his weekend trips.)

Trump’s recent game with Japanese Prime Minister Shinzō Abe further developed a warm rapport that showed when they conferred after North Korea fired a ballistic missile while the duo were at Trump’s Mar-a-Lago club. Abe’s grandfather, Prime Minister Nobusuke Kishi, laid the roots of a landmark security treaty with the U.S. during a game with Dwight Eisenhower. And Singapore leader Goh Chok Tong first broached a free trade agreement with Bill Clinton when the president invited him to golf.

Of course, golfing doesn’t always work. Just ask Obama, whose much-hyped tee-off with Republican House Speaker John Boehner in 2011 failed to break political gridlock. (Maybe that’s why none of Harry Truman, Herbert Hoover or Jimmy Carter bothered.)

While political leaders may like the game, it’s been declining in popularity among everyone else. According to the National Golf Foundation, just 24.1 million Americans played golf in 2015, down from a peak of 30 million in 2005.