MANCHESTER, N.H. ? It may seem paradoxical, but New Hampshire is poised to close down the race for the Democratic presidential nomination and launch a wide-open Republican contest.

The difference is that Barack Obama, the winner of the Iowa Democratic caucuses, can well repeat his victory here over Hillary Clinton and John Edwards. But Mike Huckabee faces much steeper odds in duplicating his Iowa win on the Republican side.

While Huckabee shattered Mitt Romney’s strategy by winning Iowa, where Romney had invested massively in advertising and organization, he is likely simply to empower John McCain to repeat his 2000 victory in New Hampshire.

A second Romney loss would effectively end the former Massachusetts governor’s candidacy – a victim of a campaign that lost its credibility along with its ideological definition.

But McCain and Huckabee have yet to build broad constituencies among mainstream Republicans. Huckabee’s following is centered among evangelical Christians, who dominated the low-turnout Iowa caucuses. McCain’s greatest appeal is to Republican-leaning independents who powered his 2000 victory and who remain loyal to him.

McCain has been endorsed by more than two dozen New Hampshire newspaper editorial pages, a major boost to his standing among independent voters.

The uncertainty facing Huckabee and McCain is heightened by their relatively meager campaign treasuries and by the shortage of time for further fundraising before the expensive Feb. 5 primaries in California, New York and other major states.

That opens at least something of an opportunity for Rudy Giuliani and Fred Thompson to demonstrate their ability in Florida, South Carolina and other states that were part of George W. Bush’s political base. The mainstream Republicans in those states are still looking for a candidate.

That search becomes more urgent as the major party politicians come to understand that Obama could be the most electable candidate the Democrats have fielded in many years.

If that seems a hasty judgment, consider what Obama already has demonstrated. Running in two of the “whitest” states in the country, Obama has shown crossover appeal that defies conventional wisdom about the limits a black candidate will face.

It is a pattern of his brief political life. When he ran for the Senate in Illinois in 2004, Obama scored well both in small towns and rural areas far from Chicago, and in the Republican-oriented suburbs.

The Obama campaign exploited that crossover appeal by having him camped in the small towns of Iowa and in suburban Boston areas of southern New Hampshire for weeks on end.

Over the summer months, Obama honed the elements of a stump speech with a polish that enabled him to deliver it without notes a half-dozen times a day – with perfect pitch. Backing his personal appeal with an organizational effort that was underestimated by both the Clinton and the Edwards campaigns, which had a year’s head start, Obama showed Democrats a combination of campaigning and organizational skill they had not seen from any candidate in their party since Bill Clinton first ran for president.

If he can demonstrate that combination again Tuesday in New Hampshire, this race would be a lot closer to being finished than anyone might have guessed even a week ago.

Hillary Clinton has one more chance to stop Obama’s momentum here. New Hampshire has been good to the Clintons in the past. They need the state to come to their rescue one more time.

She cannot count on help from anyone else. Joe Biden and Chris Dodd, two veteran senators, have left the race with their personal reputations intact but with little political reward for their efforts.

Bill Richardson is hanging on, but with only a modest hope of securing second place on the ticket.

Edwards claimed a degree of satisfaction by edging Clinton for second place in Iowa. But since his populist appeal failed to win in that state, with its rich tradition of rewarding that kind of campaign, it is hard to imagine him doing better in New Hampshire.

Any way you view it, the race is now Obama’s to lose.