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) -- After spending two years on health care, President Barack Obama is about to take up another Herculean political challenge: taxes.
In response to the Republican plans to cut spending, Obama is pushing a proposal of his own, which will include loophole-closing tax reform and increasing taxes on the wealthy. In his speech at George Washington University, the president said:
"I say that at a time when the tax burden on the wealthy is at its lowest level in half a century, the most fortunate among us can afford to pay a little more. "
By injecting taxes into the mix, Obama enters into perilous territory. For decades, Democrats have mostly tried to avoid any proposals that increase taxes.
Ever since Democratic presidential candidate and former Vice President Walter Mondale admitted that he would raise taxes in the 1984 campaign, his colleagues have avoided that kind of statement. The major exception was President Bill Clinton, who in 1993 proposed increasing taxes to cut the deficit. He persuaded Congress to pass his plan, though Democrats paid a huge political cost for doing so.
As Obama moves forward with this plan, he needs to lead the way as the White House tries to frame the debate. One of the keys to the political success of Republicans in the past two years has been their ability to shape public debate.
Some commentators have claimed that Republicans have done well because public opinion is on their side. There is some truth to this argument given that polls do continually express an antipathy toward government. Yet this explanation confuses as much as it illuminates. Many polls suggest a different underlying reality. The same public that dislikes government wants their Social Security and Medicare, just as an example.
So public opinion is an important factor, but it isn't sufficient to explain how Republicans rebounded and why Obama has encountered political difficulty.
Most importantly, Republicans have succeeded in framing how key proposals are discussed in the media. Even when the party was at its lowest point following the 2008 election, Republicans refused to cede ground.
When Obama put together a health care package which, by historic comparison, was middle of the road (looking much more like Mitt Romney than Ted Kennedy), Republicans branded it as a socialistic intervention into the economy.
They did the same with his economic stimulus plan, even though many moderate and even conservative economists at the time agreed that the spending was necessary. Since the midterm elections, the Republicans have been able to reframe the national debate around deficit reduction. The GOP has succeeded in making deficits rather than creating jobs the issue of the day, and they have pushed the president toward focusing on these questions.
Republicans have also proved to be relentless and united in their approach to the media. Despite internal divisions within the party, Republicans stay on the same page. Even when critics point to huge discrepancies between what Republicans are saying and what their plans will do -- such as the fact that Paul Ryan's proposal would actually have a limited impact on the size of the deficit -- the Republicans are not deterred. They keep hammering home the same points in interview after interview.
Finally, Republicans negotiate from positions of strength.
The party leaders have tended to take proposals that come from the extreme right wing of the party and use those proposals as the basis for their negotiations. During the recent budget debate, they used the House Republican plan to cut $100 billion from spending and worked downward from that. The advantage of this approach, even when it risks allowing Democrats to paint the GOP as extremists, is that it pushes debate rightward so that when a compromise is finally reached, the "center" is farther to the right than when they started.
The president has employed a very different style. As many of his liberal critics say, he tends to bargain with himself.
The White House separated itself from the base of the Democratic Party at the very beginning and then began the negotiations based on the terms set by the GOP (even when Democrats controlled Congress). While the strategy helped Obama to pass a significant amount of legislation, it did little to obtain Republican support and it has resulted in his moving farther away from core Democratic positions.
Now that Obama has entered into the deficit debate with proposals of his own, he will have to figure out how to sell taxes to the public.
He could reach back to the arguments of Presidents Franklin D. Roosevelt and Lyndon B. Johnson, who connected tax increases to the sacrifice that citizens must make in difficult times. Or he could use the economic growth that occurred under Clinton after his tax increase as proof for why real deficit reduction is so important. He might also drive home how many Republican presidents, including Ronald Reagan, accepted loophole reform and tax increases.
Importantly, the shift of public debate toward deficit reduction offers Obama as much of an opportunity as a danger. The fact is that substantive deficit reduction won't take place unless higher revenue is part of the package. Spending cuts alone won't do the trick.
But if Obama does not recalibrate his political strategy, he could weaken his own standing, as well as the standing of congressional Democrats, going into 2012.
The opinions expressed in this commentary are solely those of Julian E. Zelizer.