With the long marathon for the Democratic nomination now transformed into a sprint, Vice President Gore and Bill Bradley tried yesterday to turn voters' attention to the large question that has often gone unanswered during months of snappish exchanges over campaign tactics and policy disputes: What would their presidencies be like?

Bradley was first to give his answer in a morning speech in New Hampshire--where the critical first-in-the-nation primary is just four weeks away--using airy, lyrical language as he presented himself as a cleansing force who can rid American politics of reflexive cynicism. He pledged to "create a politics for this new age, in which nobility of purpose becomes accepted because people once again see that government has a real and true role in their lives."

In contrast to some of the fuzzy language about his ideas, Bradley offered some of his most pointed criticism to date of Gore, even without condescending to utter his rival's name. "Only those who have never left Washington have missed the lessons of the last decade," Bradley said.

The fact that Bradley, in a speech that aides described as a campaign centerpiece, only glancingly addressed policy made for a vivid contrast with Gore. Speaking at a high school gym in Iowa, where caucuses occur in three weeks, the vice president drew explicit contrasts with Bradley on issues and, most pointedly, leadership style.

"The presidency is not an academic exercise," Gore told a Davenport crowd. "It's not a seminar, where you get to entertain a single grand theory. The presidency is a long, resolute, day-by-day fight for people--on all the challenges they face in their daily lives."

Gore's delivery was animated, crisp and conversational--a contrast for a candidate who sometimes takes on a pedantic tone for major policy speeches or simply turns up his volume to a throaty roar for purely political speeches.

He pivoted off recent comments by Bradley citing Ronald Reagan as an effective president because he campaigned and governed around a small number of big ideas. Unlike Bradley, who has said expanding health care coverage would be his preeminent domestic priority, the vice president said he believes the next president can and should seek to do many things.

"I have different models for the presidency--leaders like Franklin Roosevelt, John Kennedy and Lyndon Johnson," Gore said. "They knew that we had to proceed on all the great unfinished business of our society."

But the most obvious precedent for Gore's proposed governing style was the man who gave Gore his job. For all that the vice president in 1999 tried to distance himself from President Clinton's personal problems, the Iowa speech suggested that in important ways Gore envisions a Clinton-style presidency.

Clinton often bemoans political "false choices," insisting that deficit reduction and increased domestic spending can go hand-in-hand, or that increased environmental regulation can enhance economic growth. Similarly, Gore said, "If we do these things the right way, we don't have to choose--nor should we."

And, just as Clinton's State of the Union speeches tend to be rapid-fire recitations of policy ideas, so too did Gore try to hit every key: preserving Medicare, subsidies for preschool, increasing the minimum wage, overhauling farm policy and so on.

Bradley did not avoid specific issues altogether. He cited his plan to dramatically expand federal government assistance for health care, with a goal of making coverage nearly universal, as well as his proposal to help localities hire 600,000 new teachers. He repeated his call for handgun registration, a more aggressive gun-control stance than Gore has proposed. But for the most part he tried to frame his brand of progressive ideology in spacious themes rather than specifics.

Speaking in an old brick mill in Manchester that has been converted to a computer-and-robot center, Bradley said the country faces a technology explosion that is "going to be like going from a horse and buggy to a Corvette."

"We must use our prosperity and our new technology to lift up those who are struggling, and ease the uncertainty that so many Americans still have about their economic well-being," he said. "Sometimes in America, our collective memory is short. . . . But it's in such times of prosperity that we must recall the lessons we learned in adversity."

Yesterday's dueling speeches suggested that both candidates recognize that the campaign has, with the new year, entered a new phase--this week alone, the presidential candidates in both parties face off in two debates. Voters are no longer merely browsing. They are trying to answer a threshold question: Would this candidate seem plausible in the Oval Office?

The former New Jersey senator, sporting a rich tan after four days in West Palm Beach, Fla., had rehearsed the speech as if it were a State of the Union address, complete with an early visit to the site and late-night practice with the TelePrompTer. Gore aides similarly had been touting the vice president's speech for several days.

Gore seemed alert to criticism that his blunt charges against Bradley sometimes comes off as mean or even demagogic. He wrapped his criticism in civil language. "Senator Bradley is a good and decent man. He has the right intentions," Gore said. "But I believe that on many issues, he has the wrong plans."

The vice president tweaked Bradley for his pose, in debates and appearances, that it is demeaning for Gore to unleash such a sustained assault on Bradley's health care plan. "Is there anyone in this room who thinks we should simply accept a total change in our health care system at face value--with no debate, no discussion, no dissent?" he asked.

Gore also said Bradley is trying to "draw an artificial distinction" on campaign finance reform, saying he too supports a major change in how elections are financed. Gore said that as long as 20 years ago he was in favor of public financing of elections and that "I still think this is the best way to go" but that as a "second-best" alternative he backs the more limited McCain-Feingold legislation, which has languished.

For his part, Bradley is no longer employing his tactic of brushing off Gore's criticisms as unworthy campaign nonsense. While Gore has presented himself as the more fiscally responsible candidate, Bradley yesterday released an analysis contending that Gore's proposals would overspend the nation's budget surplus "by as much as $350 billion over 10 years." The Gore campaign has said Bradley's health care plan alone would eat up most of the expected non-Social Security surplus over 10 years and has estimated that his other plans would cost at least $100 billion more.

Bradley criticized Gore's more measured--and less expensive--plans. "There are those voices that say we can't do big things anymore--that we can just tinker around the edges, offering small solutions to big problems," Bradley said. "But I say now is not the time to be timid."

Bradley, who twice quoted President Franklin D. Roosevelt, noted that his fireside chats were so powerful because they were a collective event, with millions of Americans huddled around their radios, while "the only thing Americans do at the same time anymore is watch the Super Bowl."

"Today, if FDR was alive, he'd have a Web site, and he'd speak on radio and television and cable," Bradley said. "He'd e-mail his text to millions, and you'd be able to find instantly and download an audio version from www.fdr.com--and watch a virtual fireplace at the same time."

Harris reported from Iowa, Allen from New Hampshire.

CAPTION: Bill Bradley cleans his TelePrompTer as he rehearses his speech on the millennium at a science and technology center for youth in Manchester, N.H.

CAPTION: Vice President Gore enters West High School in Davenport, Iowa, where he spoke about education and stressed a commitment to a big agenda if elected.