NASHUA, N.H. -- Joe Biden knows what it would take to break into the top tier of the presidential contest.
"If I played Powerball and won $100 million," said the Democratic candidate. "I'm not being facetious. Literally, people would go, 'The guy can spend like Romney. He can spend 20, 50 million bucks of his own money. Gotta put him in the top tier.'"
Class warfare, or at least class envy, is alive and well in the 2008 campaign. Those at the top command constant media attention. They reap millions in donations and soar in their private jets. The long shots, short on cash, waste hours in airport lines, waiting for their middle seat in coach. Most have been campaigning for more than a year, but they seldom make the news.
Many in the lower tier boast resumes at least as good as those of the top candidates. But anemic poll numbers create a vicious cycle that makes upward mobility extremely tough.
Attracting campaign contributions is difficult, which means less money for organizing and advertising, which makes it harder to lift poll numbers, which makes money-raising even harder.
Mike Huckabee, who ranks last in fundraising among Republican candidates, is running what he calls "a very frugal" campaign. But stretching a buck might have reached a limit when his staff booked him a room at one cheap Houston hotel where, according to Huckabee, he was the only guest who wore a shirt with sleeves.
"I thought I was going to get mugged," said the former Arkansas governor.
Last weekend, Huckabee finished a surprise second in the Iowa Republicans' straw poll and immediately went on national TV to declare himself a "first-tier" candidate. He said he had spent a total of $150,000, "down to the paper clips," in Iowa, while Mitt Romney, who finished first, shelled out an estimated $3 million.
It was Huckabee's pulpit-inflected speaking talent, not money, that produced the sort of headlines ("Huckabee, Iowa Poll's Real Winner?" - Wall Street Journal) that second-tier candidates dream about.
Huckabee, a former Southern Baptist minister, "is our Barack Obama," said an admiring adviser to Sam Brownback, a competitor for the support of social conservatives, who was hurt by finishing behind Huckabee in the straw poll.
There are no such early tests to sort out the contenders on the Democratic side, where tension levels are rising and reinforcing an atmosphere of chilly competition that, veterans say, is a departure from past campaigns.
Hillary Rodham Clinton and John Edwards piqued several lower-status rivals recently when they were caught by an open microphone during what they thought was a private chat. Clinton said that "our guys should talk" when Edwards suggested holding "more serious" debates with a smaller group of candidates, in what was seen by several long shots as an attempt to get them off the cluttered debate stage.
Earlier this year, on the morning after a South Carolina debate, Sens. Christopher J. Dodd and Biden had to get up at 5:30 a.m. for a five-hour trip back to Washington for an important Senate vote. Neither Clinton nor Barack Obama, with private planes at their disposal, offered a seat.
Biden said that, in his first presidential run, "if Jesse Jackson had a plane or if Dick Gephardt was going back for an important vote, he'd say, 'I'll give you a ride.' Not any more."
The gulf between the front-runners and the rest of the field isn't the only divide that has opened up. There are now classifications inside each party's second tier.
Stuart Rothenberg, an independent analyst, rates those at rock-bottom as "no shots," with no realistic chance of winning: Democrats Dennis J. Kucinich and Mike Gravel, and Republicans Ron Paul, Tom Tancredo and Duncan Hunter.
In between are the "credible" or "serious" long shots, with at least a remote chance to get nominated: Biden, Huckabee, Dodd, Brownback and - since his dizzying plunge from the top tier - former front-runner John McCain.
What makes these men - serious, accomplished politicians with distinguished records on the national or state level - continue to grind it out in the face of long odds?
Every dark horse can cite poll data showing that only a tiny fraction of voters have made up their minds. A candidacy that falls short still might yield an also-ran a seat in the winner's Cabinet, or even the vice presidency.
There are the uplifting, and well-worn, tales of once-obscure contenders who made it to the White House or rescued seemingly hopeless campaigns. Four years ago, with Howard Dean looking like a Democratic cinch, Sen. John Kerry had to mortgage his house to keep his candidacy afloat until the primaries began, then won the nomination.
"You can't do it unless you believe that you've got to be the one," said Richard Ben Cramer, author of What It Takes, an epic chronicle of presidential campaigning. "You've got to have that bedrock certainty that it's got to be you."
Biden, in an interview, said it is both "insulting and flattering" to be remembered as the man who was "the Barack Obama of the Democratic Party" in 1988, when he made his first White House try. Now, at 64, he's a respected senior senator, an important voice on foreign policy and, he would argue, much better qualified to be president.
"If you ever wanted to be president, this it the time to be president. No bull," he said. "The next president literally has it within his or her power to change the direction of the world."
The Delaware senator has contributed perhaps the most influential idea of the '08 campaign: a "soft-partition" plan to divide Iraq into separate Shiite, Sunni and Kurdish regions, while retaining a weak central government. It has drawn increasing interest from his Democratic rivals and, reportedly, the Bush administration.
But he struggles to compete against better-financed rivals. A private jet, he says, would cost about $400,000 a month and cut the round trip between Washington and Iowa from 16 hours to four.
Campaign appearances before small groups of voters impress Democrats and independents, who say Biden's winning them over with his speaking skills and command of the issues.
"He's definitely got a passion about him that I didn't sense last time," said Sy Mahfuz, an oriental rug dealer, after Biden's Rotary Club speech in Nashua, N.H., the other day. He admitted he hadn't seen the candidate's face on the news much but had "no idea why."
Biden does: "The problem is, you pick up the newspaper, you turn on the television, it's a Barack-Hillary show."
He plans to begin airing his first ads soon, in Iowa, where he's stuck near the bottom with about 2 percent support. He admits that trying to break through is a "torturous" effort and that his low standing can be dispiriting to friends and supporters.
"I kid my family, I say, 'The best place to be is out there'" at campaign events, Biden said. "Because you know you can win when you're out there. You come home, and you're sitting there, you go, 'God, this is over. I mean, this is done.'"