TO HELP ELECT Republicans in Tuesday's midterm elections, President Bush drew liberally on his political capital; but instead of depleting his account, he has wound up with more. Credited by all sides as the big election winner, Mr. Bush can now can be expected to act quickly to tap that nest egg to further his agenda. With both houses of Congress controlled by his party, he has an opportunity to promote judicial appointments, a homeland security department and other items that stalled in a Democrat-controlled Senate. But the victory comes with a challenge: Most Americans will likely hold Mr. Bush and his party responsible for the course of the economy and the country in the next two years, while the president's ability to act remains limited by the country's close partisan divide. Democrats could be tempted to react by stepping up their opposition to the White House's agenda; if they can avoid appearing blatantly obstructionist, the GOP might be blamed for the resulting impasse. Mr. Bush seems to perceive the problem: Yesterday, as the president deliberately refrained from a public victory lap, his spokesman Ari Fleischer said the lesson drawn from the election "is for people to work together across the partisan aisle to get things done for the country." But similar pledges of pragmatism at the time of Mr. Bush's inauguration were, at best, only sporadically observed during his administration's first two years. Whether the much-promised change in Washington's tone occurs likely will depend on how the president uses the next few months.

It may be that partisan politics will be subsumed by a crisis or a war, as the administration continues its campaign to disarm Iraq. But the first domestic test may well be Mr. Bush's handling of a still-shaky economy, which the White House defined yesterday as a top priority, along with homeland security. The fragility of the recovery from last year's recession prompted the Federal Reserve to cut interest rates yesterday; the worry is that interest cuts alone will not be enough. Mr. Bush has an opportunity to strengthen the rebound with measures that would win broad congressional support. One would be appointing a successor to Harvey Pitt as chairman of the Securities and Exchange Commission who will rebuild investor confidence -- which means avoiding candidates with ties to the accounting lobby. Mr. Bush should also consider a fiscal stimulus centered on an extension of unemployment benefits, a policy that blunts hardship while getting money to the people most likely to spend it. In contrast, making the 2001 tax cut permanent -- a partisan goal that Mr. Bush frequently mentioned on the campaign trail -- would worsen the nation's long-term deficit without doing much to stimulate short-term economic activity.

Progress on the economy, homeland security or a host of other postponed issues will also, of course, depend on how Democrats react to Tuesday's results. House Minority Leader Richard A. Gephardt (D-Mo.) effectively kicked off the intra-party debate with his reported decision yesterday not to seek reelection as leader. The initial response of many party activists has been to blame the leadership for failing to clearly lay out an alternative agenda, and to demand that the Democrats clarify and sharpen their differences with Mr. Bush. There is certainly some truth to that critique: While ducking an all-out debate with the president on Iraq, the Democrats tried to make the economy the focus of these elections without tackling issues such as Mr. Bush's tax cuts for fear of undermining the dozen senators who voted for them. Democrats are short on credible leaders and visible conviction.

But the mere embrace of a platform won't help Democrats recover if it serves to move the party away from the place near the political center that it has occupied during the past decade. If Mr. Bush this time around makes good on his promise of bipartisanship, neither Democrats nor the country will be well served by reflexive obstructionism in Congress. If, on the other hand, he chooses to spend his new capital on aggressively pressing a conservative agenda, as he has through much of the past two years, Democratic restraining influence -- still feasible in a closely divided nation -- may well prove valuable, both to the party and to the country.