James Fallows in The Atlantic:
The most famous story about modern presidential campaigning now has a quaint old-world tone. It’s about the showdown between Richard Nixon and John F. Kennedy in the first debate of their 1960 campaign, which was also the very first nationally televised general-election debate in the United States. The story is that Kennedy looked great, which is true, and Nixon looked terrible, which is also true—and that this visual difference had an unexpected electoral effect. As Theodore H. White described it in his hugely influential book The Making of the President 1960, which has set the model for campaign coverage ever since, “sample surveys” after the debate found that people who had only heard Kennedy and Nixon talking, over the radio, thought that the debate had been a tie. But those who saw the two men on television were much more likely to think that Kennedy—handsome, tanned, non-sweaty, poised—had won.
… Who Will Win the Presidential Debates Between Donald Trump and Hillary Clinton? – The Atlantic Never has the dominance of the image over the word seemed more significant than this year, as the parties and the public prepare for the three general-election debates between Hillary Clinton and Donald Trump that are scheduled to begin September 26 (as it happens, the anniversary of that first Kennedy-Nixon debate) and the one vice-presidential debate between Tim Kaine and Mike Pence, scheduled for October 4.The word scheduled is necessary because of the element of the unforeseeable that Donald Trump has brought to this entire campaign cycle. The Commission on Presidential Debates, an independent organization that has run the general-election debates since 1988, ultimately relies on reputational rather than legal leverage to get candidates to appear. If one candidate were to back out on short notice—just hypothetically, let’s say Donald Trump—it could not force a normal debate to take place. In late July, Trump appeared to be setting the stage for not debating, or changing the terms of engagement. Just after the Democratic convention ended, he sent out a tweet saying, “As usual, Hillary & the Dems are trying to rig the debates so 2 are up against major NFL games. Same as last time w/ Bernie. Unacceptable!” At the Republican convention in Cleveland, the longtime Republican activist and current Trump ally Roger Stone told me that Trump would appear as planned and “debate circles around Hillary Clinton,” as he had with his opponents in the primaries. A month later, news reports said that the ousted founder of Fox News, Roger Ailes, would be helping Trump prepare for the debates. Obviously, everything about the Trump campaign has been improvisational, and he may recalculate until the last minute as to whether he has more to gain or lose by showing up.