Pity the president, first among equals, obliged by the pulls of democracy and of his office to be "equal" and also be "first" all at once.

Picking a leader, people look for somebody well above average, stronger and brighter, with superior judgment, keener intelligence and the ability to be calm under stress. At the same time, he must be approachable, cool and in some sort of touch with the people he works for, or lose a key part of the human connection that is a critical source of his strength.

The first six presidents were aristocrats of different varieties, four Virginians and two Bostonians, who made themselves into classical scholars. It was the seventh, Andrew Jackson, who was the first to come from and rise out of the unprivileged classes, to be followed by a melange of generals, Roosevelts, log cabin babies and even some sons of the great middle class, all trying to be both a part of and apart from the people, a struggle of no small import and consequence, as Tevi Troy in his book on the White House and popular culture makes quite abundantly clear.

A chasm divides the world before 1900, when mass culture consisted of books, magazines and live theatre performance, from the world after it, when, in short order photography, radio and movies burst forth, followed by television and then social media, giving politicians new ways to speak and connect with the public, along with new chances to fall on their face.

As masters of media, Theodore Roosevelt and John Kennedy stand by themselves, having not only co-opted popular culture but become heroes in it, marketing their personae and those of their families to boost their political brands. Backed by leisurely venues (Hyannis and Sagamore), beautiful women (Alice and Jackie) and adorable children (Quentin and John-John), they are the two presidents who became true celebrities, better known for their personalities and their family dramas than their well-honed political chops.

Ronald Reagan, a pro at three dominant forms of pop culture -- radio, TV and film at the peak of its influence -- was also a master, giving the phrase "acting president" a whole new dimension. At the opposite end of this spectrum was Richard Nixon, whose attempts to be hip produced surreal moments, which yielded their own form of truth: "You dress kind of strange, don't you?" Nixon asked Elvis Presley, resplendent in purple, who answered the president, "You got your show and I got mine."

Nixon's administration marked the moment at which popular culture, which thus far had been neutral, took a decided turn against conservatives and the Republican Party, and so far has never turned back.

With mixed success, Hollywood and the pop music industry threw themselves behind George McGovern in 1972, behind Gary Hart before he imploded, behind John Kerry, who was not successful, and in 1992 behind Bill Clinton, whose saxophone riff on the late-night Arsenio Hall show was a signature piece of political theatre that George H. W. Bush couldn't match.

President Obama, our first pure product of popular culture, returned the favor by running more as a cultural brand than political candidate, adding the fashion world to the film-TV-pop-music trifecta, as the accessory everyone wanted to have. This was enough to elect him, but not to successfully drive his agenda, showing the power and limits of culture. His tale has much to say to all politicians.

And Troy's "What Jefferson read, Ike Watched, and Obama Tweeted" has something to say to us all.

Noemie Emery, a Washington Examiner columnist, is a contributing editor to The Weekly Standard and author of "Great Expectations: The Troubled Lives of Political Families."