‘You liar!’ Author reveals Trump’s super-sketchy secret for winning bogus golf championships
Donald Trump playing golf, as he has about 30 hours a week during his presidency. (Screenshot)

The author of a new book that exposes President Donald Trump as an inveterate golf cheat said he could no longer stay silent about what he'd seen and heard.

Rick Reilly, the longtime Sports Illustrated reporter and columnist, told MSNBC's "Morning Joe" that he decided to come out of retirement to write a new book, Commander In Cheat, because he was tired of Trump dishonestly bragging about his golf game.

"If he cheats on the course, he'll cheat in business," Reilly said. "If he's honest and fun on the course, he'll be honest and fun in business."

The president has repeatedly boasted that he's won 18 club championships, but Reilly said he knew the truth.

"I'm like, 'You liar!'" Reilly said. "'Because you told me how you did it when I played with you years ago.'"

The veteran sportswriter revealed Trump's sketchy secret for winning championships.

"He said when he buys a new course he plays the first round by himself, and calls that the club championship," Reilly said. "So I started calling around, people said, 'Yeah, one day he was at Trump Philly, and we played the club championship at Trump Bedminster, and he called and said, 'Who won the championship?' They said 'Joe Shmoe' shot 76, Trump goes, 'I shot 73 up here at Trump Philly, make me the champion.'"

Reilly said Trump shamelessly posts himself as the champion at each one of his golf courses, and then used those phony titles to promote his presidential campaign.

"When you walk into the clubhouse, his name -- instead of 'Joe Shmoe,' it's Trump," he said. "The thing that bothers me -- okay, golf, fine. But when he started campaigning on this as, 'I'm a winner, I can close out, I've won 18 club championships, and that's against the best players.' That bothered me. I don't know anything about politics, you guys know about politics, but I know about golf. You don't get to do that."