Editor's note: Julian E. Zelizer is a professor of history and public affairs at Princeton University's Woodrow Wilson School. His new book, "Arsenal of Democracy: The Politics of National Security -- From World War II to the War on Terrorism," will be published this fall by Basic Books. Zelizer writes widely about current events.
Julian Zelizer says the 2012 Republican presidential primary campaigns have already begun.
PRINCETON, New Jersey (CNN) -- The first hundred days is barely over and the Republican primaries for 2012 have begun.
Minnesota Gov. Tim Pawlenty has announced he won't seek a third term, immediately stirring speculation that he is preparing to run for president.
Former Massachusetts Gov. Mitt Romney has been delivering speeches on many key issues, ranging from national security to tax cuts, keeping himself in the public eye.
Former House Speaker Newt Gingrich called Judge Sonia Sotomayor, a "reverse racist." This is one of many statements that he has been making in recent months to define his agenda and position himself as a leading candidate in the Republican Party. He then backtracked from his original statement which had not played well in the press or politically.
Since the day that the McCain-Palin campaign closed shop, Gov. Sarah Palin has never stopped running. She has appeared regularly at Republican fundraisers, conventions and speaking events as well as in the media.
President Obama must govern in a political environment where Republicans are already in full campaign mode. There are many reasons behind the polarization that defines Washington, but the endless campaign is one of the most important.
Obama must try to find bipartisan compromise at the same time that many in the GOP are seeking to distinguish themselves from his administration's policies in order to define their candidacy for 2012. The media is already devoting substantial attention to the horse race that is taking shape. Every vote in Congress is seen through the lens of the next primary and general election.
Given that the primary system gives particular influence to party activists who are usually on the extreme end of the political spectrum, potential candidates are forced to think about how their decisions will play to them rather than moderates.
Of course, this phenomenon is nothing new. Indeed, Obama began his campaign in February 2007, and some say he was eying the White House from the moment he was elected to the U.S. Senate in 2004.
Presidents have always been forced to contend with the next election from the moment they begin their time in the White House. There has never been a firewall separating policymaking from electioneering.
When John F. Kennedy took over as president in January 1961, he was immediately worried about how potential Republican candidates would take advantage of any proactive stand on civil rights to steal away support from Southern Democrats in 1962 and 1964.
As Lyndon Johnson escalated America's involvement in Vietnam in spring 1965, he was already thinking about how any sign of "weakness" would benefit Richard Nixon, who was starting to publicly criticize LBJ for not doing enough to achieve victory.
When Nixon began his presidency in 1969, he decided to make a series of dramatic moves in the realm of national security -- such as gradually withdrawing troops from Vietnam and planning détente with the Soviet Union -- with the hope of broadening his coalition of support among moderates and undercutting the enthusiasm for Democrats like Edmund Muskie or George McGovern.
But without question, the endless campaign has accelerated dramatically in scale and scope. Quasi-formal campaigning has become much longer and more intense since the 1970s, when party reforms made primaries the sole mechanism through which presidential candidates were selected.
The reforms had aimed to give more power to voters rather than party bosses, who once made these decisions at the conventions during the summer before the general election. One unintended consequence was to increase the pressure on candidates to start campaigning earlier, because they needed to become known among voters.
When Jimmy Carter used a victory in the little-known Iowa caucus to propel himself into the media spotlight in January 1976, future candidates saw greater incentives to start as early as possible so to improve their chances of winning in Iowa and New Hampshire.
In recent years, states have competed to move their primaries earlier on the schedule in order to ensure the candidates and media pay attention to them. This "front-loading" has created even more pressure on candidates to start selling their message as early as possible.
Primaries are not the only reason that candidates are running earlier. Candidates are desperate to attract private funds given the astronomical cost of running a campaign. To attract donors it is important to look like a winner. To look like a winner, candidates need to have their name in circulation before the media deems some candidates to be the front-runners.
This creates a vicious fundraising cycle. Candidates start running earlier so they can make money, but running earlier costs more money. After the 2008 Democratic primaries, we now have front-loaded systems where candidates will still feel the race might last until the very end. That requires even more money.
The endless campaign thus encourages the flow of private money into our political system. That makes it difficult for promises of change to ever be fulfilled. On K Street, the home of the Washington lobbying industry, the new president quickly learns that the new boss is the same as the old boss.
Is it possible to break this cycle? In general, the opportunities for reform are limited barring a radical change to our election process that would make our system look more like Europe -- where elections are usually shorter, cheaper and publicly funded.
One potential reform has to come from the media. If the major news outlets devote more attention to policymaking and less to the statements of potential candidates, there will simply be fewer opportunities for people like Romney (or any comparable Democrat when a Republican is in the White House) to run this early. Nobody will be listening. The endless campaign thrives on receiving media attention.
The second change has to come from government. The White House and Congress must tackle campaign finance reform and attempt to restore some of the system that had been put into place as a result of the Watergate scandal. Only with public finance, enforced contribution limits and possibly expenditure limits would the nation be able to dampen the fundraising pressures on candidates.
Until these and other steps are taken, presidents will have to govern constantly in a campaign season -- as will the opposition party. And the policymaking process -- as well as public confidence that government officials have their eye on the public rather than on the ballot box -- will suffer as a result.
The opinions expressed in this commentary are solely those of Julian Zelizer.