This is a guest post by political scientist Julia R. Azari of Marquette University. She is the author of “Delivering the People’s Message: The Changing Politics of the Presidential Mandate.

On Tuesday, Obama joined the ranks of celebrities like Charlize Theron and Justin Bieber by appearing on comedian Zach Galifianakis’ Web-based show  “Between Two Ferns.” The president’s ultimate purpose in doing the interview was to promote, but he didn’t introduce the Web site and phone number until after he and Galifianakis had discussed Dennis Rodman’s diplomatic trips to “North Ikea,” Obama’s possible disappointment over term limits (no, said the president, “it would be sort of like making a third ‘Hangover’ movie”), and birth certificates.

Although this particular brand of humor may have been something new, modern presidents have periodically tried to cultivate a less formal image and to engage the public through new forms of media. Presidents sometimes use these tactics to challenge ideas of strong, distant leadership, as Obama did this week; at other times, leaders have used these tactics to actually reinforce conventional definitions of leadership.

In his first term, Obama did an AMA (Ask Me Anything) live chat on reddit, and broke into song during public appearances, impressing audiences with his rendition of Al Green songs. Bill Clinton played the saxophone on “The Arsenio Hall Show” and discussed his preferences in undergarments on MTV. Before the Internet and MTV, Jimmy Carter appeared on television in a plaid shirt and a cardigan (on separate occasions), and participated in an unscripted live call-in show.

In these instances, presidents tried to convey intimacy and informality, thus challenging the notion of the presidency as a formal, distant and powerful office. Instead, they communicated the message that the president was just a regular person, a participant in everyday culture. Each had a compelling political reason to do so. Challenging a conventional image makes news. Carter was reacting to the backlash against a strong executive in the wake of Watergate and Vietnam.  Clinton sought to distinguish himself from George Bush, who was often criticized for seeming aloof and out of touch. These strategies fit into a democratic (small-d) understanding of the president as an ordinary American citizen.

Other presidents have pursued intimacy and informality in their communications, while simultaneously underscoring – rather than undermining – conventional notions of a strong, masculine and distant presidency. FDR’s use of “Fireside Chats” is one example. Using the new medium of radio, FDR drew on “Hollywood-style” storytelling and spoke directly to an electorate that could listen to the president’s voice piped into their homes. FDR’s use of radio in the 1930s was comparable to Obama’s use of Web-based media – new technologies have allowed presidents to innovate in the way they relate to audiences and package their messages. But for FDR, the intimacy was an illusion created by the delivery – the tone and content of the messages was confrontational and presented the image of a president with firm control over policy, especially early on.

Ronald Reagan provides a useful comparison as well. His use of television and radio are generally regarded (from a communication standpoint) as mastery rather than innovative. But, Reagan used self-deprecating humor, which has also become a trademark of Obama’s unconventional media participation. However, like FDR, Reagan’s informal and familiar choices were paired with rhetoric that stressed the strength of the nation and the office.

It’s tough to gauge the success of presidential communication. However, FDR and Reagan were more successful communicators in this sense: Their rhetorical frames have had considerable staying power, and both had a large impact on what the public expects from presidents. The historical evidence suggests that presidents who want to be more casual and familiar with audiences, or who want to harness new modes of communication, enjoy more success when they do this in a way that affirms conventional ideas about leadership.

Obama’s  appearance Tuesday clearly challenges these conventional notions of the presidency. Galifianakis asks him what it feels like to be the “last black president,” and asks with a sigh, “What are you plugging?” when the president mentions  Obama gives as good as he gets, telling the comedian that he won’t let Michelle near him and asking, “What’s it like for this to be the last time you ever talk to a president?”

One question that remains is whether pairing informality with strength in the mode of Roosevelt or Reagan would even be possible for Obama, given current political conditions. It’s difficult for contemporary presidents, particularly Democrats, to strike the right balance and appear strong but not excessive. The Democratic Party has sought to distance itself from the concentration of executive power, especially in reaction to the Bush administration, only to face similar accusations. Under those circumstances, any efforts to project strength will likely be fraught and muddled.

The impact of Obama’s unconventional move remains to be seen. The polarized state of American politics probably means that not much will change anytime soon, as far as the president’s public standing and influence. Liberal sites such as the Daily Kos heaped praise. The video has also attracted some unsurprising criticism from the right. Traffic appears to be up at the site, which, of course, was the immediate goal. In the long term, we may see whether a president has finally succeeded in changing what it means to “look presidential.”