It’s the question Democrats would rather not ask in their moment of revelry: Are their new majorities in the House and Senate sustainable?

What if the war in Iraq is over by 2008? Or what if it is still being waged despite Democratic pledges to change the course? What if voter antipathy toward President Bush is irrelevant in two years? After all, he will be on his way out.

“Who knows whether these things are long-term trends or not,” Sen. Byron Dorgan, D-N.D., said last week.

Voters gave Democrats control of Congress but did not undergo an ideological conversion. The Democrats’ success had more to do with anger toward President Bush, weariness over the war and contempt for the corruption and scandal in Congress – a confluence of negatives that became a political force.

As some Democrats begin looking to 2008 and beyond, the challenge is how to turn antipathy toward Republicans into affection for Democrats.

“You can’t count on that kind of a wave in every election by any means,” Democratic pollster Mark Mellman said.

Sen. Charles Schumer of New York, the chairman of the Senate Democratic campaign committee, acknowledged that the Democrats’ 51-49 majority in the Senate was the result of the narrowest of victories in six races. “Had 10,000 votes flipped, we would have four seats, not six,” he said.

Democrats do see opportunities ahead.

In 2008, there are 21 Republican Senate seats up for election and only 12 Democratic seats. Eight of the Republicans in those seats won their last election with 55 percent or less of the vote.

In the House, where Democrats held 230 seats and appeared to be in line to win two more, all 435 members face re-election in 2008.

“The good news for Democrats is that we don’t need a wave to keep the seats we have,” Mellman said.

Democrats came into power calling for a change in course in Iraq. They promised to clean up government, create better economic conditions for the middle class and ensure cheaper drugs for the elderly.

“People are open to a longer-term Democratic majority,” Schumer said, “but we have to seal the deal.”

Schumer proposed a three-step plan for Democrats.

It would begin with modest plans to increase the minimum wage, provide more tax breaks on college tuition, encourage greater energy independence and require drug companies to negotiate for lower Medicare drug prices.

Democrats then must work in bipartisan fashion to confront the war in Iraq and government deficits, Schumer said.

“Thirdly, we have to try our best to come up with a full vision and platform that points toward ’08,” he said.

To some Democrats, the party’s biggest task is maintaining credibility on national security.

Since the Vietnam War, Republicans have held an advantage with voters on defense and security issues. But the Iraq war soured many voters on Republicans. By early fall, polls showed the public trusted Democrats more on resolving Iraq and trusted them equally with Republicans in combating terrorism.