Editor's note: Julian E. Zelizer is a professor of history and public affairs at Princeton University. He is the author of "Jimmy Carter" published by Times Books and editor of a book assessing former President George W. Bush's administration published by Princeton University Press.
Princeton, New Jersey (CNN) -- Sarah Palin's new reality show looks like it might become a hit.
During its first week, "Sarah Palin's Alaska" attracted almost five million viewers, the best that a premiere has done on the TLC network.
The same week that the show debuted, there were reports that Palin was talking with insiders about a presidential run. She told ABC News that she believed she could defeat President Obama in 2012.
The launch of the show has felt very much like the start of a presidential campaign.
If this turns out to be true, Palin's reality show could be a harbinger of campaigns to come. We might be witnessing the start of a new era in presidential campaigning, where candidates take their message directly to the voters while avoiding almost any filters in the process.
For much of the 20th century, party bosses played the central role in the nomination process. In the famous world of "smoke-filled rooms," party leaders determined which candidate would be best. They evaluated a number of factors, ranging from party loyalty to regional appeal before deciding on the ticket. Primaries had existed for much of the 20th century, but they were not central.
The concept of the smoke-filled room gained its fame from a moment at the 1920 Republican Convention in Chicago, Illinois. None of the Republican nominees had secured the nomination.
The New Republic noted that "the nominee will be selected in Chicago possibly at the convention, perhaps in a hotel room ..." The magazine was right.
At the Hotel Blackstone, the party bosses selected Ohio's Sen. Warren Harding, after the delegates deadlocked on the two front-runners, Gen. Leonard Wood and Illinois Gov. Frank Lowden.
Democrats had similar moments before the 1970s.
In 1952, the Democratic Party decided that Illinois Gov. Adlai Stevenson should be the party nominee rather than Sen. Estes Kefauver, who had won most of the primaries. The party bosses felt that the Tennessee senator, who had gained notoriety as a result of his televised hearings into organized crime, was too difficult to control.
This system, in which party bosses were the brokers between candidates and voters, broke down in the late 1960s. The chaos at the 1968 Democratic Convention led many younger members of the party to believe that the nomination process had to be reformed or the party would keep choosing candidates who were out of touch with voters.
"When parties have been given the choice of reform or death in the past," Sen. George McGovern of South Dakota said, "they have always chosen death. We are going to be the first to live."
Party reforms began with the Democratic Party and spread to the Republicans. In addition to democratizing the rules for picking the delegates, the reforms made primaries the main mechanism through which candidates would be chosen.
While the old party bosses faded, new political forces stepped into the vacuum. The news media gained immense power. Television and print reporters greatly influenced how primary and caucus voters came to perceive candidates and helped determine who was a front-runner and whose campaign was failing.
In 1976, former Georgia Gov. Jimmy Carter, an unknown candidate, ignored the party bosses and directly courted the news media.
They couldn't get enough of Carter, who promised to restore trust in government in the aftermath of Watergate. When Carter won the Iowa caucus, reporters declared him the front-runner. He played the game of media expectations perfectly and went on to victory.
The news media changed the nature of campaigning. Candidates were forced to speak in shorter sentences in their effort to articulate the sound bite that made the nightly news. Image started to matter much more, as candidates crafted their campaign events with an eye toward how they would appear on television.
It is unclear what will come next. The news media has been undergoing rapid transition. Newspapers have been struggling around the country, with some city papers closing down. The television news media has greatly fragmented as a result of cable, while more channels feature hosts who are openly partisan.
"Fake news" and other satirical shows, such as Comedy Central's "Daily Show" with Jon Stewart, are now important outlets for politicians. The news cycle now runs 24 hours a day, while the editorial controls on the dissemination of information have broken down as a result of the internet.
One of the most striking developments has been that candidates have more opportunities to take their message directly to voters.
To be sure, this opportunity is not entirely new. During the 1980s, U.S. Rep. Newt Gingrich of Georgia and other young Republicans made floor speeches on C-SPAN to communicate directly to voters without having to go through reporters.
Palin is taking this a step further by starring in her own reality show. It is too early to tell if this reality show is anything more than a one-time spectacle. But if this signals the beginning of a new era, the danger is that voters will no longer be able to count on any kind of intermediary to interrogate candidates and to help determine their relative strength for either party.
Unlike political advertisements, it is more difficult for viewers to see these kinds of shows as advertisements or as staged performances. By design, the shows give the appearance of offering viewers a glimpse of reality.
For all their flaws, and there were many, both the party brokers and the news media did put candidates through a process that tested them in the public arena and brought to light information about their politics.
That objective news media still exists and it has been joined by web-only news sites that sometimes offer this kind of analysis, as do the remaining metro papers that are now accessible around the world through the internet. But with the fragmentation of the media, it is more difficult for those outlets to claim the attention of a large numbers of voters.
They are competing with channels, sites and blogs where reporters wear their politics on their sleeve. The outlets that attempt to offer objective analysis will continue to feel intense pressure to play to the more partisan style that seems to command the most viewers and readers.
If the nation does shift toward an era of direct campaigning, the process would likely deteriorate. Voters will be exposed to a constant stream of infomercials. Much of the media, now more polarized than ever, won't be reliable as a source of objective analysis, but rather will function as a cheering section for one of the two teams in Washington.
We will enter deeper into a world of virtual politics where it is difficult for voters to tell fact from fiction and too easy for politicians to promote an image and arguments that have little basis in reality.
The opinions expressed in this commentary are solely those of Julian E. Zelizer.