Former President Bill Clinton, husband of Democratic presidential front-runner Hillary Clinton, manipulated Donald Trump into running for president on the GOP ticket because he believed it would weaken the party and hand the election to his wife, Ed Klein writes on his website, EdwardKlein.com.

"Bill Clinton is rubbing his hands with glee and taking full credit for Donald Trump’s mounting problems — his belligerent handling of Fox’s Megyn Kelly and his refusal to rule out a third-party bid," Klein wrote.

He quoted "political insiders" as saying that Clinton was up to his "usual shenanigans" when he called Trump in late May to encourage him to run for president.

News of that phone call leaked just ahead of Thursday's debate, and two GOP candidates made reference to it. Businesswoman Carly Fiorina, who appeared in the afternoon debate of lower-tier candidates, noted that she had not received a call from Bill Clinton. In the main debate, Kentucky Sen. Rand Paul interjected that Trump is "already hedging his bet on the Clintons."

Klein said that Bill Clinton judged that former Florida Gov. Jeb Bush was Hillary Clinton's biggest obstacle to winning.

"He figured — rightly — that a Trump candidacy would put a crimp in Bush’s campaign and sow confusion in the GOP ranks," he said.

"Bill is a master at reading other people’s weaknesses, and he predicted that Trump — who never lets a slight or insult go unpunished — would go ballistic under tough questioning by Fox News anchors during the first Republican president debate."

Clinton was "thrilled — but not surprised," Klein said, when Trump threatened to run third party if he isn't treated well by the GOP establishment.

"That was music to Bill ears, because it would split the Republican vote and hand the election to Hillary," Klein said. "It’s not surprising, therefore, that Bill Clinton thinks he was the real winner of last week’s Republican presidential debate."