There has never been anything like it.

This week, Texas Gov. George W. Bush will make the first trip of his presidential campaign. Normally, presidential campaigns begin as small and lonely undertakings--a candidate, an ambition, an old friend to drive the car. Standing on a sidewalk hoping people will stop and talk to you. Loitering outside a factory at dawn. Maybe there is a reporter along.

The Great Bush Unveiling will take place under the withering gaze of some 200 reporters and photographers from around the world. Overflow audiences are expected for many of his events, and chances are good he will lead the network newscasts. No rehearsal, no off-Broadway tryouts--this campaign is going directly to prime time.

"It is monumental--a challenge no presidential campaign has ever had to deal with at this stage of the race," says Haley S. Barbour, former Republican Party chairman and a member of Bush's exploratory campaign committee.

First in the polls, first in endorsements, piling up money faster than an Internet IPO, Bush is the hottest candidate the country has never seen. Until now, he has hunkered down in Austin, tending to the Texas legislature and enjoying life in the grand old pile that is the Texas governor's mansion. There has been plenty to enjoy: Legions of Republicans from the around the country have filed past, pleading with Bush to enter the race.

Eventually, he has to campaign, however. And now his extraordinary early success creates its own set of problems.

How can he show up in Iowa and New Hampshire--where the preferred style of politicking is one-to-one, handshaking, coffee-sipping and baby-kissing--trailing an entourage numbering in the hundreds, without looking hoity-toity?

How can he chat with folks if dozens of cameras and boom mikes are pressing in on him?

How can any candidate be relaxed when, his very first day out, every step, word and bead of sweat is being studied by scores of writers?

"I think he knows there is no way to be completely prepared for it," says David Beckwith, Bush's deputy press secretary. "The whole thing is comparable to a major event for an incumbent president, except that the intensity will be even higher because of the pent-up demand."

The candidate is poring over drafts of a stump speech. His staff fires question of the sort they imagine the press might ask. When the Texas legislature adjourned and Bush held a news conference last week, one Dallas reporter gave him a preview of things to come by asking the governor's position on "vertical integration of agriculture."

But the media is no tougher than the voters Bush will encounter on his tours of Iowa and New Hampshire. Two small states with giant impact on presidential politics, they jealously guard their special access to candidates. Voters in these states want to be touched, listened to, called by name.

Political pros call it "retail politics," and it is a Bush specialty. Set loose in a crowd, the bright-eyed governor is a shoulder-grabbing, cheek-kissing bundle of charm. The upcoming trip, though, will be retail only in the sense that Wal-Mart is retail.

For months, the small but rapidly expanding Bush campaign staff has been trying to figure out the balance between personal contact and media exposure. Cater too much to reporters, and voters might conclude Bush is arrogant or grandstanding. Ignore the press and . . . well, in politics it is generally considered a bad idea to ignore the press. Defenders of freedom and keepers of the flame of truth though they may be, reporters also have a tendency toward whining, carping and pickiness.

And there are further layers of complication. Here's just one: Keeping the press on a short leash requires a lot of help. It takes a bunch of people to steer, feed and corral 200 journalists. But the Bush campaign is reluctant to employ too many minions--it might not look humble enough.

Karen Hughes is the person in charge of finding the answers. She is Bush's communications director and one of his closest aides; she has a quick laugh and an engaging homeyness. "The national press corps is a strange group to ask for mercy," she says, "but we'll probably end up doing exactly that."

The campaign is going to come down on the side of the local voters, although Hughes and others don't frame it precisely that way. Bush plans to do a lot of local television interviews; in Iowa he'll spend hours shaking hands at fund-raising picnics hosted by two House members, Republicans Jim Nussle and Greg Ganske; he'll visit a fire station and a diner in New Hampshire.

Bush "puts a lot of effort into personal communication," says Beckwith. "I expect C-SPAN is going to want to mike him up"--that is, attach a wireless microphone to the candidate as he works the crowds--"but that's not going to happen. He wants to have as private a conversation as possible with individual voters, given 200 press hanging around."

Saturday will be the first day out. Bush, along with some key staff members and about 100 reporters, will board a chartered plane in Austin and fly to Cedar Rapids, Iowa, where scores more reporters will be waiting. At one event after another, reporters can expect to be herded into roped-off bullpens--typical when covering an incumbent president, but unheard of this early in a challenger's campaign.

At least the press will be able to see the candidate most of the time in Iowa--if only from afar. Iowa is big on outdoor events. Classic Iowa campaign venues include fairgrounds, grain silos and hanging out with farmers next to rusting tractors.

After the frenzy in Iowa will come a relatively slow day. Bush doesn't like campaigning on Sundays--last year he abandoned a blitz by GOP candidates because the final day fell on a Sunday. The candidate will spend that day in Kennebunkport, Maine, at the Bush family summer home, where he'll help to celebrate his father's 75th birthday.

Then the horde will be bused to New Hampshire, where politics is more likely to be practiced indoors. New Hampshire is the land of the Diner Drop-by, the General Store Walk-through.

Bush plans to visit at least one diner and a firehouse during his day in New Hampshire. It's hard to fit 200 extra people into a New Hampshire diner. So for events like these, the campaign will have to choose a few journalists to form a "pool" that will follow Bush around and report back to the rest of the pack. "The campaign will be biased in favor of the voters' access to an interaction with Governor Bush, as opposed to the media getting everything it wants," says Barbour. "The risk, of course, is some reporters will whine about that, even write bad stories."

The campaign is willing to take such risks--especially if it means giving Bush a chance to do what he does best as a campaigner: press the flesh. For all other risks, the campaign wants to figure them out and head them off. For example, Brian Montgomery, a former White House advance man who is handling preparations for the trip, recently went shopping for extra toothpaste and toothbrushes--in case reporters' suitcases go astray.

History's biggest maiden campaign voyage is being planned by a relatively small group of longtime Bush loyalists. The senior staff is growing so rapidly that some top aides don't know each other. At a recent senior staff meeting, campaign manager Joe Allbaugh said the speechwriter should travel to see Bush in action. Fine, said the scheduler, looking at the speechwriter. "But who are you?"

Karen Hughes laughs again when she recounts this tale.

"We're going to make mistakes," she says. "We're only human. But we've been calling everyone we know asking for advice. People from the Bush White House and from the Reagan years. We need all the help we can get. . . .

"In fact," she adds mischievously, "if you read this story and have any ideas, please--please--call us."

CAPTION: Texas Gov. George W. Bush visited San Antonio educational center last week. This week, the prospective presidential candidate goes national.