My last column explored some reasons for the bitter liberal-conservative polarization of our political class, which has helped spawn the anger, mendacity, and emotionalism that make our politics so ugly. Here I explain how the Supreme Court and the media have made this polarization worse, and sketch possible remedies.

The justices’ most obvious contribution to political polarization has been a succession of rulings over the past four decades, many of doubtful constitutional merit, that have infuriated conservatives and, lately, liberals too. These judicial fiats have laid down the law in absolutist terms on divisive issues previously resolved through democratic deliberation and legislative compromise. Roe v. Wade is the leading example. That 1973 decision suddenly swept aside all 50 states’ abortion laws. At the time, many liberal, pro-choice scholars considered Roe a gross distortion of the Constitution. Even Justice Ruth Bader Ginsburg, then the nation’s leading feminist lawyer, wrote in 1985 that "the Court ventured too far in the change it ordered and presented an incomplete justification for its action." Perhaps more important, Roe spurred a huge backlash, helping to launch the Religious Right movement that has driven so many moderates out of the Republican Party.

Liberals were no less infuriated four years ago, when the five more-conservative justices made George W. Bush president by ending the Florida Supreme Court’s chaotic manual recounts. Liberal law professors widely trashed Bush v. Gore as legally indefensible. Some accused the majority of a nakedly partisan act. I strongly disagree. But given the unavoidable appearance of partisanship inherent in the 5-4 split, it might have been wiser to give the Florida court another chance, while ordering it to devise more-reliable vote-counting rules.

One irony is that Bush v. Gore’s legal holding was derived from one-person, one-vote precedents laid down by liberal justices in the 1960s. And those decisions, which were dramatic departures from the original intent of the 14th Amendment’s equal protection clause, have themselves been a major cause of political polarization. The reason is that they have greatly aggravated the gerrymandering of election districts — the drawing of odd shapes in pursuit of various forms of political advantage. As I detailed last week, the bipartisan species of gerrymandering, designed to entrench incumbents, has filled the House of Representatives and many state legislatures with the most conservative of Republicans and the most liberal of Democrats. It has also eliminated most of the moderate centrists who once greased the wheels of comity and compromise.

Gerrymandering is probably older than the Republic. But in recent decades, it has become far more extreme. The most publicized explanation is the development of computer technology making it possible to draw convoluted lines pulling in (or excluding) pockets of Democratic or Republican voters with remarkable precision. But the Court deserves much of the blame, because of the unintended but foreseeable impact of its one-person, one-vote rulings and two subsequent lines of redistricting cases.

The one-person, one-vote rulings were justified in striking down the gross malapportionment of many election districts. But they went too far by banning even the slightest differences in House districts’ population. This created more opportunities for gerrymandering mischief by requiring every state both to redraw its election districts after each decennial census and to create strange shapes if necessary to equalize their populations. Then came a 1986 decision construing the Voting Rights Act as virtually requiring racial gerrymanders to maximize the number of safe districts for black and Hispanic politicians. The result was to elect very liberal Democrats in the new "majority-minority" districts and very conservative Republicans in the surrounding, "bleached" districts. Finally, since 1993, a more conservative 5-4 majority has used the equal protection clause to ban racial gerrymanders that look too "bizarre." Unless, that is, the purpose of the gerrymander is not to create safe black and Hispanic districts, but to create safe Democratic and Republican districts!

The common thread is that while blundering around in the political thicket, the justices have both mandated more-frequent redistricting and smashed the traditional criteria that used to act as built-in restraints on gerrymandering. Compactness, contiguity, political subdivision lines, natural boundaries — all have been cast aside in headlong pursuit of equipopulous exactitude and racial correctness. The result has been ever more bizarrely shaped, ever more conservative and liberal districts.

Can this mess be fixed? The politicians who benefit from it seem unlikely to fix it. Should the justices themselves give it a shot? They have been urged to strike down partisan gerrymanders such as those engineered since the 2000 census by Republicans in Pennsylvania, Florida, Michigan, Ohio, and Texas. They recently told a lower court to keep alive the Democratic challenge to the Texas gerrymander.

Past performance suggests, however, that the current justices might only make matters worse. A decision striking down excessively partisan gerrymanders, for example, would require hugely subjective judgments and might only exacerbate polarization by fostering more bipartisan gerrymanders. The best hope may be the appointment of new justices who understand the need to reverse the effective disenfranchisement of many centrist voters.

In any event, better districts could do only so much good as long as most voters are woefully uninformed about public issues and many others are selectively informed by biased news outlets. Politically incorrect as it is to criticize voters, the vast majority have only the most rudimentary understanding of the big issues. They spend little time looking beneath the surface of TV news, which focuses on strident rhetoric and sensational allegations. That’s why no presidential candidate dares speak candidly about, say, the expert consensus that we need higher gasoline taxes and smaller cars to curb oil consumption.

One of our democracy’s saving graces is the opportunity created by the nearly even divide between Republican and Democratic partisans, both those who are uninformed and those so blinkered by ideology that their views are immutable. The opportunity is for the minority who are well-informed, open-minded, and independent to tip the balance. But that vital voter contingent seems to be shrinking.

The main reason may be the increasing segmentation of the news media into two groups. One — including Fox News, most talk-radio programs, The Washington Times, The Weekly Standard, and National Review — slants much of its factual reporting (as well as editorial commentary) to the right. The other, much larger group — including NBC, ABC, CBS, CNN, NPR, MSNBC, The New York Times, The Washington Post (excepting its admirably thoughtful editorials), The Los Angeles Times, USA Today, and even The Wall Street Journal (excepting its tiresomely tendentious editorials) — is a bit more balanced but still slants to the left.

A few decades ago, many conservative, as well as liberal, Americans trusted their daily newspapers and broadcasters to report the news in a genuinely fair and balanced fashion. Not now. Consider this critique: "If you think The [New York] Times plays it down the middle on any of [the big social issues], you’ve been reading the paper with your eyes closed…. The editorial page [is] thoroughly saturated in liberal theology…. In the Sunday magazine, the culture-wars applause-o-meter chronically points left. [News articles often] tell only the side of the story [the staff’s] co-religionists wish to hear…. Readers with a different worldview will find The Times an alien beast."

Another conservative screed? Hardly. Those are the words of Times ombudsman Daniel Okrent, a Democrat. No wonder so many conservatives have tuned out The Times and other mainstream media. The unfortunate result is that more and more conservatives get almost all their news from conservative media, while liberals get theirs from liberal-leaning media. Both camps can choose news sources to reinforce their biases, flatter their self-regard, and omit or downplay inconvenient realities.

So conservatives and liberals increasingly live in separate worlds. In one, the Bush invasion has made Iraq into a vast pool of blood and arena of torture, a lost cause. In the other, American liberators are fighting terrorists, opening schools, and nurturing nascent democracy. In one, Republicans are disenfranchising black voters to steal the election for Bush. In the other, Democrats are orchestrating rampant fraud to steal it for Kerry. Only the shrinking minority of people who have the time and interest to consult multiple news sources and challenge their own assumptions have a common frame of reference.

Calling all billionaires: What this country needs is a good national newspaper that will play the facts straight. A good national news network, too.