After its questionable debate performance, it seems that Mr. Trump’s carefully constructed political persona may be starting to deflate. Although his performance during the debate was less antagonistic than many people expected, it was clear at the end that Hillary Clinton was a better prepared candidate, with a stronger grasp of the issues. In addition, although Trump questioned her “stamina” she seemed to be in better shape than his opponent when the debate ended.

Presidential debates have a long and interesting history in the U.S., and can have a decisive influence in the final result of the presidential election. Nobody can forget the negative effect that Nixon’s poor personal appearance had in people’s perception after his debate with John F. Kennedy.

Kennedy had prepared carefully for this debate and was clearly in better physical shape, while Nixon was tired from a presentation he had done earlier that day. In addition, he refused makeup and voters found a person tired, sweating and looking even older than normal, in sharp contrast with Kennedy’s youthful appearance.

Another famous presidential debate was the one between Gerald Ford and Jimmy Carter which was held in 1976. On that occasion, Gerald Ford said the words that, according to many observers, doomed his chances for the presidency: “There is no Soviet domination in Eastern Europe and there will be none under a Ford administration.” Those words showed his lack of knowledge of a political issue critical to world peace, his campaign momentum stopped and Carter won the election.

Humor, when well timed, can have significant consequences against an opponent. Ronald Reagan, who was a master of well-timed deliveries thanks to his long experience as an actor, used humor in two presidential debates. In 1980, Reagan responded to Jimmy Carter’s repeated attacks with a phrase since then made iconic, “There you go again…”

In 1984, Reagan repeated this formula in his debate with his Democratic rival Walter Mondale, Reagan, then 73 years-old said, when asked if, at 73, he wasn’t too old to be president, “I will not make age an issue of this campaign. I am not going to exploit, for political purposes, my opponent’s youth and inexperience.” His answer provoked a laugh even from his opponent.

That Donald Trump lacked the charisma of those leaders was amply shown in last night’s debate with Hillary Clinton. It didn’t help that he refused to acknowledge ownership of his own past statements, such as when he stated that climate change was a hoax perpetrated by the Chinese. As Hillary Clinton said, “Donald, I know that you live in your own reality,” to strong audience approval.

It didn’t help Trump either also his acknowledgement that he took advantage of existing laws in declaring six bankruptcies and not paying taxes. Rather than offering clear proposals to rebate Clinton, Trump, with his characteristic disrespectful behavior towards women kept interrupting her speech saying “Wrong, wrong,” to the evident annoyance of Lester Holt, the moderator, who tried to move the debate forward.

In a typical exchange that showed the differences between both candidates Clinton said, “In fact, Donald was one of the people who rooted for the housing crisis. He said, back in 2006, ‘Gee, I hope it does collapse, because then I can go in and buy some and make some money.’” Well, it did collapse. With his characteristic insouciance Trump responded, “That’s called business, by the way.”

To Trump’s angry street fighter persona Clinton offered a calm behavior, self-assured and with a clear grasp of the facts. By many criteria, Clinton was a winner of the first debate and, barring unpredictable events, her initial performance should assure her the presidency. To Mr. Trump’s detriment, presidential debates matter.