His comments came after Trump threatened on Saturday to put Gennifer Flowers, a woman with whom Bill Clinton has said he had an affair, in the front row of Monday's debate. Trump's warning came as a result of Hillary Clinton's campaign giving Cuban what he called a front-row seat at the Hofstra University affair. Trump's campaign later confirmed Flowers was not invited.
"First of all, when I tweeted that I was going to sit in the first row, I didn't have a first-row seat," said Cuban, the owner of the NBA's Dallas Mavericks and star of ABC's "Shark Tank."
"I knew that it would get under his skin and drive him crazy. Mission accomplished," he added.
"Second, I got tickets because I wanted to bring my 13-year-old daughter, whose birthday it was yesterday," he continued. "Unfortunately, we've been getting death threats, and Trumpians have been trying to hack everything we have, so I've had to spend too much time on security and protecting my family. So that's unfortunate, I don't blame that on Donald, that's just part of the game. Third, I'm not here to cause a scene."
Speaking to Business Insider earlier Monday, Clinton campaign spokesman Brian Fallon said it "says more about" Trump than Cuban that the Republican nominee was "so easily rattled."
"Both campaigns invite surrogates and supporters to come and be here for the debate and talk to the media around the debate, that's happened in previous election cycles, Trump's doing it," he said. "You know, I haven't seen his full list but I expect Sen. [Jeff] Sessions will be here, Mayor [Rudy] Giuliani, Gov. [Chris] Christie, you know, and all of those surrogates of his have had plenty of unkind things to say about her, and she's not going to let that bother her."
"So to us, it's just interesting that one particular supporter of Hillary Clinton's who's been doing campaign events has gotten so clearly under Donald Trump's skin," he continued. "I think that says more about Donald Trump and his ability to be so easily rattled than it does about Mark Cuban."
Cuban called it "the honest-to-God truth" that he just wanted to bring his daughter to the event, and that his goal was not to provoke Trump from the audience.
But, he added, if Trump makes eye contact with him, he's got a plan.
"I'm going to smile," he said.
He said he wanted to attend the event because "it's a historic event" and that this election has sparked him to become more political.
"I've been apolitical my whole adult life," he said. "But I think this election's different, and it concerns me. I just don't think Donald Trump will be a good president, and I think Hillary will be, could be, a better president."
"Donald Trump has no will to prepare," he continued. "You see that in all his responses to everything. You know, he had that, had he made that effort the kind that Coach Bobby Knight expects from his team to win, it might have been a different story back when I liked what he was doing. It was a breath of fresh air until I realized he didn't have the will to prepare, and that was really big for being president in my mind."
He used a famed quote from Knight, a Trump supporter, from when he was head men's basketball coach at Indiana University, where Cuban attended college: "Everybody's got the will to win, but it's only those with the will to prepare that do win."
Cuban added that "he didn't switch from" Trump to Clinton "without doing my homework."
He also said Trump's business experience does not prepare him for the presidency.
"I asked him on the phone one time, I said, 'you do realize you'll have to make decisions that people die as a result of,'" he said. "And, just no response."
Cuban has been a Clinton supporter since he endorsed the Democratic nominee at a Pittsburgh rally in July, and he has ripped Trump repeatedly on social media and in interviews, calling him the most "dangerous" presidential candidate he can imagine during a recent interview with Business Insider. Cuban recently offered Trump $10 million to hold a four-hour policy debate with him.
Earlier in the cycle, he was more enthralled by a potential Trump presidency, and at different points said he'd be interested in serving as either Trump or Clinton's running mate.