THE long and bitter presidential campaign will (it is widely and devoutly hoped) be over in nine days. One man will win, and the voters will be rewarded with either George W. Bush's ''ownership society,'' with sweeping change in Social Security and an overhaul of the tax system, or John Kerry's ''stronger America,'' with a huge new health program and other assistance for the strained middle class.

Right?

Actually, probably not.

Theoretically, it could work that way, with a bitter campaign producing a robust mandate, functional control of the government for one party and a season of legislative accomplishment. But not many in Washington expect it to happen this time.

To begin with, whoever wins on Nov. 2 will face determined resistance on Capitol Hill. As Newt Gingrich, the former speaker of the House, put it, ''Neither side is going to get a 1964-style landslide.'' A President Kerry would probably face, at the very least, a Republican House. A second-term President Bush could face a Democratic Senate, but even if the Republicans retain control, their majority is expected to fall well short of the 60 votes needed to break Democratic filibusters.

The winner will also be left with a budgetary legacy -- the proverbial deficits as far as the eye can see -- that will make the grand goals of the campaign trail very hard to achieve. And the situation in Iraq will be a steady drain on resources, political capital and presidential energy.

Moreover, either a President Kerry or a re-elected President Bush would have to cope with a poisonous political climate that is unlikely to suddenly improve when the election is over, and in fact, has steadily worsened over the past decade. There is a long and happy tradition of divided government in the United States -- the framers, after all, built the system with checks and balances to make it hard to do anything too big, too fast -- but this is something different.

''There's more bitterness now, more hatred,'' said former Senator Warren Rudman, the New Hampshire Republican. ''If Kerry wins this election, you'll have a huge number of Republicans who are absolutely boiling about it, and will be as tough on him as the Democrats were on Bush.''

In short, if the campaigning was hard, the governing could be brutal. And the intensely partisan struggle over each man's domestic agenda will not end, but simply move to another arena.

This is not to say the next president won't have immense power, especially over foreign policy. Mr. Bush underscored the extent of those presidential powers over the past four years, with his projection of American force abroad.

But ''domestically, you can't do anything by yourself,'' said Morris P. Fiorina, professor of political science at Stanford and a senior fellow at the Hoover Institution. A president can make use of administrative orders and regulations to advance policy in many spheres, including the environment, without a vote in Congress. And the next president may have the opportunity to nominate as many as three new justices to the Supreme Court, given that eight of the nine current justices are 65 or older. That could shape the court for a generation, potentially shifting the balance on issues like abortion rights.

There too, though, the next president will run up against the limits of the current political divide. If a re-elected Mr. Bush nominates a justice who favors overturning the Roe v. Wade decision establishing abortion rights, as many of his supporters expect him to do, he would very probably touch off an ideological and political war. Liberal advocates, including the aggressive and well-financed advocacy groups battle-tested by this year's election, would enter the fray with gusto.

In fact, Representative Barney Frank, a liberal Democrat from Massachusetts, said that an opening on the Supreme Court would be less an opportunity than a ''serious dilemma'' for a re-elected Mr. Bush and his party.

Mr. Gingrich, the former Republican speaker, said that Mr. Bush could name a David Souter-like moderate and ''enrage'' his conservative base, or name a conservative and face ''a prolonged filibuster that will in the end lead to a change in Senate rules.'' Either outcome, of course, would be polarizing.

The winner of the election will undoubtedly try to deliver at least part of his core agenda. Mr. Kerry's signature domestic initiative is an ambitious program meant to provide access to health insurance to millions more children and adults, to be paid for by rolling back the Bush tax cuts for Americans making over $200,000. But how far would such a plan get in a Republican House?

Representative Bill Thomas, the chairman of the House Ways and Means Committee, with sweeping power to block health legislation he dislikes, describes Mr. Kerry's plan as ''a big dose of more government messing.''

For his part, Mr. Bush has been promising an ambitious overhaul of the Social Security system to create private investment accounts for younger workers. That proposal is anathema to the Democrats, who say that it would undermine one of the most popular and progressive government programs in history. It is hard to imagine an issue that could rouse more Democratic opposition.

Splitting the difference on these health and retirement proposals seems very hard. Ideological divisions run deep over the role of government, how much risk and responsibility should rest with the individual, and whether the social insurance programs of the New Deal and Great Society should be replaced with a more market-oriented approach.

If Mr. Bush returns with a Republican Senate and House, he could attempt to reprise what he did with last year's Medicare legislation: essentially, behaving like a man with a mandate and counting on Republican leaders to muscle his legislation through. But Republicans themselves, facing the 2006 midterm elections, are likely to be even more wary than usual of a take-no-prisoners push on Social Security.

Moreover, the experience of the Medicare expansion, the biggest in nearly 40 years, offers a cautionary lesson.

The legislation did pass, but the furious partisan debate over it continues to this day. In some ways, the new program never gained the legitimacy that comes with bipartisan consensus, and many of its intended beneficiaries remain confused and skeptical about it. Senator Olympia J. Snowe, the moderate Republican from Maine and a supporter of the legislation, said after traveling her state last week, ''It's really regrettable how the political rhetoric has so infected the program, to the point where it might deter seniors from enrolling.''

She added: ''Every issue now is being viewed as a political football, or through a political prism. At what point do we draw the line, and try to govern in the best interests of the American people?''

That, of course, raises the possibility that gridlock and partisan warfare are not inevitable for the next president -- that Mr. Bush or Mr. Kerry may be able to alter the political landscape by sheer dint of leadership. Both of them have promised to do so.

Senator Snowe says she thinks it is possible. Thomas E. Mann, a political scientist at the Brookings Institution, said he believed it would take ''an external event and political leadership'' to break the toxic combination of ''50-50 parity and ideological polarization.''

Mr. Gingrich said the polarization would not end until one side won. ''It's like the 1840's and the 1850's,'' he said. ''This is going to go on and on. This is genuine disagreement over the future of the country.''

The former speaker, often regarded as the founding father of today's hypercombative politics, added, ''This isn't a divided government -- it's a divided country.''