The Shrill One:

Now that the Democrats are strongly favored to capture at least one house of Congress, they’re getting a lot of unsolicited advice, with many people urging them to walk and talk softly if they win.

I hope the Democrats don’t follow this advice — because it’s bad for their party and, more important, bad for the country. In the long run, it’s even bad for the cause of bipartisanship.

There are those who say that a confrontational stance will backfire politically on the Democrats. These are by and large the same people who told Democrats that attacking the Bush administration over Iraq would backfire in the midterm elections. Enough said.

Political considerations aside, American voters deserve to have their views represented in Congress. And according to opinion polls, most Americans are actually to the left of Congressional Democrats on issues such as health care.

In particular, the public wants politicians to stand up to corporate interests. This is clear from the latest Newsweek poll, which shows overwhelming public support for the agenda Nancy Pelosi has laid out for her first 100 hours if she becomes House speaker. The strongest support is for her plan to have Medicare negotiate with drug companies for lower prices, which is supported by 74 percent of Americans — and by 70 percent of Republicans!

What the make-nice crowd wants most of all is for the Democrats to forswear any investigations into the origins of the Iraq war and the cronyism and corruption that undermined it. But it’s very much in the national interest to find out what led to the greatest strategic blunder in American history, so that it won’t happen again.

What’s more, the public wants to know. A large majority of Americans believe both that invading Iraq was a mistake, and that the Bush administration deliberately misled us into war. And according to the Newsweek poll, 58 percent of Americans believe that investigating contracting in Iraq isn’t just a good idea, but a high priority; 52 percent believe the same about investigating the origins of the war.

Why, then, should the Democrats hold back? Because, we’re told, the country needs less divisiveness. And I, too, would like to see a return to kinder, gentler politics. But that’s not something Democrats can achieve with a group hug and a chorus of “Kumbaya.”

The reason we have so much bitter partisanship these days is that that’s the way the radicals who have taken over the Republican Party want it. People like Grover Norquist, who once declared that “bipartisanship is another name for date rape,” push for a hard-right economic agenda; people like Karl Rove make that agenda politically feasible, even though it’s against the interests of most voters, by fostering polarization, using religion and national security as wedge issues.

As long as polarization is integral to the G.O.P.’s strategy, Democrats can’t do much, if anything, to narrow the partisan divide.

Even if they try to act in a bipartisan fashion, their opponents will find a way to divide the nation — which is what happened to the great surge of national unity after 9/11. One thing we might learn from investigations is the extent to which the Iraq war itself was motivated by the desire to have another wedge issue.

There are those who believe that the partisan gap can be bridged if the Democrats nominate an attractive presidential candidate who speaks in uplifting generalities. But they must have been living under a rock these past 15 or so years. Whoever the Democrats nominate will feel the full force of the Republican slime machine. And it doesn’t matter if conservatives have nice things to say about a Democrat now. Once the campaign gets serious, they’ll suddenly question his or her patriotism and discover previously unmentioned but grievous character flaws.

The truth is that we won’t get a return to bipartisanship until or unless the G.O.P. decides that polarization doesn’t work as a political strategy. The last great era of bipartisanship began after the 1948 election, when Republicans, shocked by Harry Truman’s victory, decided to stop trying to undo the New Deal. And that example suggests that the best thing the Democrats can do, not just for their party and their country, but for the cause of bipartisanship, is what Truman did: stand up strongly for their principles.