WASHINGTON – The mere announcement that Barack Obama was planning an exploratory visit today to New Hampshire has scrambled Democratic presidential politics in ways that belie his scant résumé as an officeholder.

As a potential candidate for the Democratic nomination, the freshman senator from Illinois poses a serious threat to New York Sen. Hillary Clinton's basic strategy as the presumptive front-runner.

Meanwhile, the rest of the field – even former North Carolina Sen. John Edwards, who was the party's last vice presidential nominee – must now be wondering whether there will be enough money and media attention left to sustain them through the early contests, including the nation's all-important first primary in New Hampshire.

Obama's immediate impact on the campaign has already captured the attention and admiration of hardened political professionals.

“He is in the process of just turning this whole thing upside down,” said Jim Duffy, a highly regarded Democratic strategist.

Obama, the son of a black Kenyan father and a white American mother, rocketed to political stardom at the 2004 Democratic National Convention with a galvanizing keynote speech that presented a vision of national reconciliation bridging the divides of race, class, gender and ideology.

The excitement continues.

“He is hot, and you simply cannot deny that heat and electricity that he is generating,” said John Zogby, a nonpartisan pollster.

On the other hand, with the curtain-raising Iowa caucuses still more than a year away, Obama might prove to be just another political flash in the pan reminiscent of astronaut-hero John Glenn in 1984, the Ohio senator who flamed out as soon as Democrats started voting for a nominee.

And there were others: former Texas Gov. John Connally in 1980; Phil Gramm, another Texas political powerhouse who was a senator when he ran in 1996; and retired Army Gen. Wesley Clark in 2004. All were major public figures whose prior résumés failed to measure their political talent or presidential stature.

However, many within the political community say they sense something unique about Obama that could spare him the indignity of an early exit from the presidential contest – should he decide to compete.

“His personality and charisma are big assets for him,” observed Dante Scala, an expert on New Hampshire politics at St. Anselm College in Manchester. “His record of accomplishments in the Senate is obviously very thin at this point. But I think there is a real sense with him that there's a lot of potential there. And there's the sense that he may represent the turning of a page in American politics, a new face, a new generation of politicians.”

Those qualities could spell trouble for others in the Democratic field. “He is enjoying popularity and a media bounce that I think is close to unprecedented in my 40, 45 years of observing this process,” said Don Fowler, a former national chairman of the Democratic Party. “I can't think of anybody who has just sort of come out of the blue and in such a short time made such a positive, comprehensive impression on just a wide range of people.”

Obama's flirtation with a presidential candidacy has already forced apparent tactical adjustments by other Democratic competitors lacking his or Clinton's star power.

Possibly fearful of being eclipsed by a looming Obama media frenzy, Indiana Sen. Evan Bayh announced last weekend – earlier than expected – that he would create an exploratory committee.

Iowa Gov. Tom Vilsack went further. He became a formal candidate and embarked on a five-state tour to promote his campaign.

“When you get a political celebrity in the race, somebody who is treated as a mega-candidate, it makes it harder for the other guys to get attention, to get on TV,” argued Stuart Rothenberg, editor of a political newsletter.

The problem also extends to raising the early cash and to attracting the savvy local activists needed in the initial round of competition for national convention delegates in Iowa, New Hampshire, Nevada and South Carolina.

“The overall effect is that it makes it that much more difficult for second-tier candidates to break out,” Scala said. “His presence sucks a lot of the oxygen out of the room.”

Obama also may threaten a key component of Clinton's base – the black vote – that might otherwise find its way to the New York senator, given the popularity of her spouse, former President Clinton, with that constituency.

That could be crucial in South Carolina, where Richard Harpootlian, former chairman of that state's Democratic Party, said Obama “basically ices the black vote, which means it will be a much more fragmented process.”

As a consistent critic of the war in Iraq who entered the Senate after the vote in late 2002 that authorized the use of force against Saddam Hussein, Obama has another significant advantage over Clinton, Edwards and Massachusetts Sen. John Kerry, the unsuccessful 2004 presidential nominee. Although they are critical of the president's Iraq policy now, they all voted to give Bush the leeway to invade Iraq, putting them at a potential disadvantage in a party that has overwhelmingly turned against the war.

Seasoned veterans such as Harpootlian caution against being swept away by a candidate who is approaching only his second anniversary in the Senate after a stint in the Illinois state Senate. Obama “hasn't had to answer a single specific question about what he would do,” Harpootlian said. “What's his position on taxes? What's his position on the budget? What would he do about the war other than having been against it in the first place? He is very articulate, very sharp, but very, very young.”

Although Obama could remain in the Senate to gain greater seasoning, many experts say his moment may be now.

“Why would you want to sit there for another four or eight years accumulating all those votes in the Senate where people then have a record to pick apart?” said Duffy, the Democratic strategist.

Stephen Hess, a presidential scholar at George Washington University who served in both the Eisenhower and Nixon administrations, agreed.

“I think he'd make a great mistake if he doesn't run, because there is a time and tide in these things. . . . Who knows where you are four years from now, eight years from now, 12 years from now?”