The cliche is that America has a 50-50 electorate, but Tuesday night it was -- adding up the vote from the Senate, House and gubernatorial elections -- more like 53-47. Democrats will be tempted to discount the result and call it a personal affirmation of George W. Bush, as well as the product of historical accident -- the fact that Bush happened to occupy the presidency at a time when the 9/11 terrorist attacks created a surge of national unity. But of such things are political realignments, potentially, made.

Ronald Reagan won in 1980 largely on charisma and on the basis of circumstances outside his control: the hostage crisis and stagflation. No doubt many other Republicans could have won that year, too. But Reagan took the opportunity afforded him and used it to remake American politics and the world. So, to say that voters' affinity for Bush may (obviously) partly explain the election in no way detracts from the opportunity that his new power represents.

Solidifying that GOP advantage from last week will require, as its most important pre-condition, continued successful leadership on the war. Bush's leadership since 9/11 has allayed the worries about his seriousness and his capabilities that dogged him during the 2000 campaign and his first nine months in office. It has created a Cold War-type environment in which defense and national security -- traditional Republican strengths -- are again central issues. And it has inoculated him against some of the Democrats' harsher charges: It's hard to believe that someone who is doing such a tremendous job protecting Americans is simultaneously scheming to push the elderly into the snow.

Some Democrats will conclude, mistakenly, that their accommodation of Bush on Iraq hurt them by robbing them of a voice on the most profound issue of the day. But the problem wasn't that Democrats attempted to skate over the fact that their hearts weren't fully in the war so much as that their hearts weren't fully in the war in the first place.

The dilemma for the Democrats, as my colleague Ramesh Ponnuru points out, is actually much larger than just deciding now whether they really support war in Iraq. If they are pro-war, they have to be so convincingly, and not just as a matter of positioning. This will require a painful rethinking of matters of war and peace. The dovish Pelosi types can't simply lie down with the hawkish Liebermans; in some sense, they must become Liebermans.

On the other hand, if Democrats decide to oppose intervention in Iraq (a little late, after last month giving Bush the unilateral authority to send American soldiers into harm's way), the war could become a classic 1980s-style wedge issue. Back then, the issues of crime and welfare forced Democrats to choose between majority opinion and their political base. They are faced with a similar choice today, between a public cautiously inclined toward war and a base still defined by the Vietnam generation's reflexive opposition to the application of American power abroad. If they side with the base, they could be forced onto the wrong side of a fundamentally important issue in a way that they haven't been since before the rise of Bill Clinton.

Assuming, however, that Democrats aren't foolish enough to self-immolate on the war, Republicans will have to push for long-term advantage on domestic policy. Despite its temporary political appeal, the Department of Homeland Security, a largely pointless bureaucratic reshuffling, doesn't cut it (it's much more important to reform the FBI and CIA). Nor does the energy bill, a dog's breakfast of subsidies to various energy interests. Nor does making the Bush tax cut permanent.

Indeed, on economic policy, Tuesday's election was mostly a battle of nothing vs. nothing, with the Democrats hurt much more by their programmatic nullity only because they didn't have national security issues or a popular national figure to compensate for it.

Bush's tax cut last year was formulated in the midst of what everyone assumed was the Perpetual Economic Boom as a statement of political morality -- i.e., "the surplus belongs to the people" -- rather than a stimulus to long-term growth.

A priority for Bush must be developing an economic policy, since continuing economic weakness would be his chief vulnerability over the next two years. He can use the small package of investor tax cuts pushed by House Republicans late this year as a starting point, and add measures to improve the tax treatment of dividends and cut the capital-gains tax to make a more substantial proposal. The White House might fear appearing too "pro-business," but nothing will so enhance the reputation of corporate America again as better profit statements and, consequently, a healthier stock market.

The other immediate-action item will be pushing for the confirmation of a raft of judges blocked by soon-to-be former Senate Judiciary Committee Chairman Patrick Leahy (D-Vt). The creation of a less liberal judiciary is crucial to the protection of conservative legislative accomplishments on everything from the environment to the war on terror to abortion. The last is one reason that judicial nominations are so important to Bush's social-conservative base.

How to handle that base will be much discussed in coming weeks. Its energy obviously made the off-year victory possible. To ensure that social conservatives turn out in such numbers again in November 2004, Bush must keep them happy. But, in doing so, he will have to resist the media's tendency to interpret any social-conservative measure as "overreaching." The post-1994 GOP congressional majority, it's worth noting, didn't overextend itself by putting too much emphasis on moral issues, but by allowing its obsession with the budget deficit to force it into proposing a sweeping, ill-considered Medicare overhaul.

One way President Clinton blunted the appeal of that Congress was by poaching on its social-conservative turf, signing a gay-marriage ban and piling up small-scale proposals -- curfews, school uniforms, etc. -- that demonstrated his sympathy for middle-class values. It's easy to forget that the fundamental divide in American politics, between red state and blue, is moral. Bush can't neglect his side of that split. A cloning ban makes sense as an early social-conservative initiative. It has already passed the House and is a pro-life measure that is overwhelmingly popular with the public.

But there is a legitimate lesson from the post-1994 Congress: Avoid ambitious initiatives, especially entitlement reform, if you haven't properly prepared the public for them. White House aides loosely talk about pursuing Social Security and tax reform before 2004. Republicans ran away from the phrase "Social Security privatization" this year, but many of them defended personal accounts, most notably Rep. Pat Toomey in Pennsylvania's retiree-rich 15th District. But that is hardly a mandate for Social Security reform. Nor would a push for tax reform, which can be hugely complicated without the compensating benefit of cutting people's tax burdens, be wise.

The White House can instead advance both reform goals incrementally by promoting tax-free savings accounts. House Republicans have already proposed more quickly phasing in higher limits on how much people can contribute a year to IRAs and 401(k)s, to $5,000 and $15,000, respectively. This would make it possible for people who don't save more than this each year -- the majority of Americans -- to have all their savings tax-free. This would mean they would effectively be in a consumption-based tax system -- providing a back-door tax reform.

Encouraging saving with these, and other, measures is also a way to promote the most important demographic trend for Republicans: the rise of mass investment. The increasing number of investors has fostered an increasing public sophistication about the economy and retirement savings. Newly savvy voters were not inclined to buy the simplistic argument this year that because Bush is president he must be responsible for the weak economy, nor did they buy Democratic attacks on Social Security reform. The promotion of IRAs and 401(k)s will ease people further into the idea of saving for their own retirement, thus taking more of the scare out of private Social Security accounts.

In recent months, amateur historians searching for a counterpart to George W. Bush have settled upon Harry Truman, another underestimated politician who, with his seemingly perfect gut instincts, forged a new strategic doctrine and international security arrangement in response to an urgent threat to America. If Bush plays his political victory this year correctly, the Truman analogy will hold with one important exception: His election to a new term won't have to be an upset. Rich Lowry is the editor of National Review.

On the economic policy front, Republicans didn't offer much more than Democrats -- but both parties will need long-term strategies before 2004. Here, House Minority Leader Dick Gephardt makes his case before Election Day.