Having the last word. Donald Trump took to Twitter on Wednesday, July 20, after his former rival Senator Ted Cruz was booed on stage at the Republican National Convention for refusing to endorse the presidential candidate. (Watch the awkward moment in the video above.) And the real estate titan revealed that he had seen Cruz's controversial speech ahead of time.

"Wow, Ted Cruz got booed off the stage, didn't honor the pledge!" the former reality TV star, 70, tweeted. "I saw his speech two hours early but let him speak anyway. No big deal!"

During the hotly contested primary battle, Cruz and other Republican contenders had vowed to support the eventual nominee, so many had expected him to endorse Trump.

Instead, while addressing delegates at the convention in Cleveland on Wednesday night, the Texas senator, who was the runner-up for the GOP presidential nomination, urged voters to "vote with your conscience."

"What if this, right now, is our last time? Our last moment to do something for our families and our country?" Cruz, 45, said. "To those listening, please, don't stay home in November. If you love our country, and love your children as much as I know you do, stand, and speak, and vote your conscience, vote for candidates up and down the ticket who you trust to defend our freedom and to be faithful to the Constitution."

As the crowd at the Quicken Loans Arena realized that an endorsement of Trump was not forthcoming, they started loudly booing Cruz and chanting "Vote for Trump" and "Say it!"

It was not a totally surprising move from Cruz, given the pair's long-running animosity. They sparred bitterly throughout the campaign for the GOP nomination, with the Celebrity Apprentice host referring to the Cruz as "Lyin' Ted" and even going so far as to imply in a tweet in March that the conservative candidate's wife, Heidi Cruz, was not attractive.

CNN reports that as the crowd began to boo the senator, his wife, who is an employee of investment banking firm Goldman Sachs, was heckled by Trump supporters shouting the company's name, and she was escorted out of the arena by security.

Presumptive Democratic presidential nominee Hillary Clinton quickly jumped on Senator Cruz's controversial move, tweeting "Vote your conscience," along with a link to her website.

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