And Obama, who has earned a reputation throughout his career as someone who actually listens to opposing views, struck a bipartisan tone with GOP governors earlier this month that could help him on Capitol Hill as well. “We are not going to be hampered by ideology in trying to get this country back on track,” Obama told the National Governors Association meeting in Philadelphia. “If you can show me something you are doing that’s working, or if you tell me that this program or this regulation is hampering us from doing smart things that will advance the interests of our state, then you’re going to have a ready ear.”

Some of Obama’s signals have been mixed. It didn’t escape Republicans’ attention that the incoming White House chief of staff will be the man who, as chairman of the Democratic Congressional Campaign Committee, helped drive the Republicans out in 2006. But it also didn’t escape liberals’ attention when Steve Hildebrand, Obama’s deputy campaign manager, pushed back against progressives’ criticism of the president-elect’s appointments, writing on the Huffington Post Web site that Obama “was elected to be the president of all the people — not just those on the left.”

There is more that Obama could do to break the partisan rut in Congress, lawmakers from both parties say. He could put pressure on House Speaker Nancy Pelosi of California and Senate Majority Leader Harry Reid of Nevada to involve Republicans in the drafting of major legislation, a level of inclusion that is rarely seen now. He could endorse proposals to overhaul the redistricting process to produce fewer polarized House districts, a step that GOP Rep. Mark Steven Kirk , one of Obama’s Illinois colleagues and a potential candidate for his Senate seat, said would address one of the underlying causes of partisan polarization in Congress.

And he could reach out personally to more key Republicans than he has so far. As of last week, for example, incoming House Minority Whip Eric Cantor of Virginia and House Republican Conference Chairman Mike Pence of Indiana had met with Emanuel, but had yet to hear from Obama directly. And when Kirk, a leader of the moderate Republican “Tuesday group,” was asked if Obama had called him yet, he responded: “Are you nuts?”

Still, no one thinks Obama should bear the entire responsibility for breaking the cycle of polarization. Democratic leaders have a responsibility to involve Republicans from the beginning in major legislation, lawmakers on both sides say, rather than simply drafting it themselves and daring the GOP to vote against it.

There’s also a consensus that Republicans, and particularly their leadership, have a responsibility not to vote automatically against whatever Obama puts on the agenda. That’s a temptation that could prove hard for many Republicans to resist, given that their ranks were reduced in the last two elections and that many of the survivors are convinced that the party needs to become more conservative to return to power.

“I think there’s a lot of good will toward the president-elect, but that won’t trump the desire to re-establish the brand, unless someone can show them another path to victory,” said former Rep. Vin Weber, a Republican who is now a managing partner in the lobbying firm of Clark & Weinstock. Altmire says it would be a “big mistake” for Republicans to move to the right, and he warns that such a strategy would make it “very difficult to build any kind of working relationship.”

And ultimately, Americans have been doing a pretty good job of polarizing themselves. In their book “The Big Sort,” authors Bill Bishop and Robert G. Cushing document how people now live in communities where everyone agrees with them politically and shares the same tastes. The authors are now finding that people are becoming polarized by income and education levels as well. In the November election, they say, higher-income and educated voters generally cast their ballots for Obama, while those with lower income and education levels supported John McCain .

And the communities themselves are becoming less politically diverse, Bishop and Cushing found. Nearly half of the vote came from counties that either Obama or McCain won by 20 percentage points or more. If the voters continue to seek political purity in their own lives, it shouldn’t be a surprise that the lawmakers they send to Congress live up to that standard in their voting records.

“To me the notion of a pragmatic, middle-of-the-road nonpartisan electorate and rabidly partisan members of Congress doesn’t quite fit the reality,” says Richard Fleisher, a professor at Fordham University in New York City. “The reason they are polarized and remain polarized is because they are responding to polarization in the electorate.”

Opportunity in Crisis

The outlook isn’t completely bleak. The severity of the economic crisis could represent an opportunity for bipartisan support to end it, even if most Republicans are wary of the stimulus bill Obama and his party are developing. And advocacy groups and political scientists see other ways that the polarization might start to end — or, at least, matter less.

Sticking Together: Click here to view chart

The term political scientists use for measures that bring polarization to an end is “cross-cutting issues,” and Bishop and others believe the economic crisis could be one of those. Sure, Republican leaders are dismissing the Democrats’ stimulus plans as simply “more Washington spending,” in the words of House Minority Leader John A. Boehner of Ohio. But there’s also the chance that Republicans who usually stick with their leadership might peel off because of anxiety about the disastrous state of the economy combined with the potential benefits both sides could see from Obama’s proposal to launch the biggest investment in infrastructure since the 1950s.

There’s also the potential for greater use of what David W. Brady, a political scientist at Stanford University, calls “inside-out coalitions” — meaning the legislation is designed from the middle and written to add appeals moving outward toward the edges of the political spectrum, until it reaches majority support. That way, the legislation might lose votes on both ends, but it still passes without creating the usual partisan divide.

That’s how President Bush and his Democratic partners, including Sen. Edward M. Kennedy of Massachusetts, won passage of the No Child Left Behind education law early in Bush’s presidency, and Brady thinks Obama could achieve a similar feat with his own education overhaul plans. He also thinks the stimulus package has potential because of the severity of the crisis. “The question is, are there any inside-out coalitions? The answer is, there are more than you might think,” Brady said.

The catch, of course, is that bipartisanship doesn’t always produce a great product simply because both sides voted for it. No Child Left Behind was one of the few bipartisan accomplishments of the Bush presidency, but it has become so unpopular that few lawmakers are proud of it now. Educators charge that it forces them to spend all their time drilling students for tests, and conservatives were never comfortable increasing the federal role in the schools. So even as the Obama team tries to break through the partisan divide, it will have to remember that bipartisanship sometimes requires policy compromises that don’t end up working in practice.

Still, Obama’s message of ending predictable, automatic partisanship clearly resonated with the public, and it certainly gave hope to centrist lawmakers such as Rep. Baron P. Hill of Indiana, whose voting record made him one of the least partisan House Democrats this year. “If there are honest differences over how to solve the economic crisis, that’s okay,” said Hill. “What I always objected to was being partisan for the sake of being partisan, and that’s been happening more and more every year I’ve been here.”

There’s always the prospect that polarized voting could decrease next year for reasons that Obama wouldn’t necessarily like. As the Democrats have expanded their majority, they’ve added members from Republican-leaning states and districts, many of whom are centrists who might feel more free to vote against Democratic priorities now that the party’s margins in the House and Senate are wider. Likewise, Altmire says he’s concerned that the Democratic leadership, for all of Pelosi’s talk of governing from the middle, might feel free to pursue a more liberal agenda, reasoning that they can afford to lose more of their members.

But even if the same pattern of polarized voting does continue next year, it may have less of a practical impact, since the wider Democratic majority in the Senate guarantees that the Republicans won’t be able to sustain as many filibusters. “You’ll be seeing the same kind of partisan voting and hailing the post-partisan era at the same time,” said Robert L. Borosage, co-director of Campaign for America’s Future, a liberal advocacy group.

Another strategy that could help the Obama team, according to political scientist David Mayhew of Yale University, is to take advantage of the opposition’s tendency to fall away once a bill has reached a threshold of support — because then lawmakers don’t want to be seen as standing in the way of a popular measure. So if Obama and key Democrats can win the support of, say, 60 percent of the House and Senate for whatever health care overhaul plan they put together, Republicans will be less likely to put up a fight.

Public Engagement

But what, if anything, can be done about a polarized public? At a time when people choose to live in like-minded communities and don’t even get their news from the same sources — conservatives choose the Fox News view of the world, liberals prefer the MSNBC version — it might seem impossible to shake up the patterns of polarized congressional voting unless Obama’s agenda can get a significant buy-in from the public.

That may be where Obama’s efforts to use technology to encourage the public’s involvement could have a long-term payoff. His transition team is soliciting online comments on health care and economic policy, and it launched a feature on its Web site last week to allow the public to suggest questions for the transition team to answer. It is also organizing “health care community discussions” throughout the country to offer people a chance to pitch their ideas for overhauling the health care system.

And the transparency Obama has promised for his administration and is already testing in his transition team — posting online copies of all of the written policy recommendations submitted by interest groups — could boost the public’s confidence as well.

“So much of the polarization is ideological. It’s really hard to break through that,” said Ellen S. Miller, co-founder and executive director of the Sunlight Foundation, a group that advocates open government. “But I think an organized citizenry can press both Democrats and Republicans to vote in favor of what’s the best public policy, rather than being dictated by ideology.”

Those are some serious expectations to pin on an administration that hasn’t even begun yet, especially with all of the other political forces that are stacked in favor of polarization. But there was one recent sign that the trend toward greater polarization might not be permanent. In a Gallup/USA Today poll taken right after the election, 57 percent of Americans said the country is more divided on issues than it has been in recent years. That’s a lot, but it was far less than the 72 percent who took the same view in November 2004.

The fact that Americans feel less divided doesn’t mean they are less divided, of course. But perceptions can mean a lot in politics. If it’s the start of a new trend, we’ll know soon enough. And sooner or later, the lawmakers elected to Congress may even get so tired of the old script — the same old partisan voting, year after year after year — that they’ll be ready to start a new one.

Shawn Zeller contributed to this story.