CONCORD, N.H. -- Inside the gold-domed New Hampshire capitol yesterday, 400 members of the state legislature listened as Sen. Robert J. Dole (R-Kan.) pleaded for their support.

Minutes later, some of the same elected officials peered from the windows on the second floor of the House chamber as Rep. Jack Kemp (R-N.Y.) and 16 other conservative Republican congressmen held a news conference on the steps of the capitol. Iowa precinct caucus winner Dole was one of the targets. And Vice President Bush, according to Sen. Gordon J. Humphrey (R-N.H.), one of the Kemp backers, was "mortally wounded" by his third-place Iowa showing Monday.

If they had been watching perhaps an hour earlier, the legislators might also have caught former Delaware governor Pierre S. (Pete) du Pont IV standing on the same steps criticizing Kemp, Dole and Bush.

Kemp barely avoided running into du Pont on the capitol steps by delaying his appearance there by nearly two hours, thus turning the waiting television cameras over to du Pont.

Never mind the Dukakis bumper stickers and the Bush lapel buttons in evidence around the state capital, or the bright blue Pat Robertson signs across the bridge at the New Hampshire Highway Hotel. Yesterday, the show was the thing.

The U.S. Geological Survey reported that a light earthquake centered about 20 miles north of Manchester rattled southern New Hampshire in the morning. It could not be immediately determined whether the quake was caused by New Hampshire adjusting itself to a new quadrennial onslaught of presidential campaign fever.

Candidates from both parties abandoned Iowa with barely a glance back, rushing to New Hampshire to offer their own versions of what Monday night's vote totals meant.

"The day after Iowa it's a brand-new contest," Dole declared here.

In getting to the starting line, candidates all but tripped over each other and the hundreds of campaign workers, reporters, producers, broadcast technicians and others who trooped into New Hampshire yesterday in preparation for Tuesday's first-in-the-nation presidential primary election.

Manchester Airport was Democratic territory for the better part of the day. Iowa victor Rep. Richard A. Gephardt (D-Mo.), New Hampshire front-runner and Massachusetts Gov. Michael S. Dukakis and Sen. Paul Simon (D-Ill.) all touched down within two hours. Jesse L. Jackson arrived later. Gephardt, who ran a relatively lonely campaign until late last month, arrived with eight Learjets.

Dukakis returned to New England in a Boeing 727 only to be greeted by a group of jeering young Simon supporters, who chanted, on behalf of Simon and his wife, "Jeanne and Paul in '88."

"This state is claimed to be the turf of the governor from across the border," said Simon's New Hampshire spokesman, Gary Galanis. "We're going to prove them wrong."

Simon, his wife and 50 to 75 reporters landed minutes after Dukakis departed. A campaign staff worker brought with them "Simon the Cat," a stray adopted in Des Moines that has become the object of superstition. When the cat vanished from Simon's Des Moines headquarters, the campaign flagged; when the cat returned, the campaign gathered momentum.

The airport confusion was so intense that at one point aides for all three candidates greeted each other like old war buddies as they waited for their candidates to arrive. Occasionally, the tension showed.

"Have you seen the Simon advance man?" snapped one anxious young Dukakis supporter. "His bus is in our way."

Buses were a good way to judge how well the Iowa campaign went for a candidate. Dole and Gephardt had three full-sized charter buses apiece. Simon had one. Kemp had a van.

The invasion should do wonders for the local economy, and perhaps for the level of political discourse as well.

Airport gift shop manager Tim DiVenuti said he ordered double his usual supply of daily newspapers, and car rental agencies ordered dozens of extra vehicles. Upstairs in the tower, four air traffic controllers engaged in their own lively political debate as they gave campaign planes permission to land.

Scores of reporters, plunked down for the first time in weeks in a state with mountains, stumbled out of campaign planes dazed by the sunlight and the reality that Iowa was not the end, but the beginning.

"Hey, this looks like the Savery Bar," said a Dukakis aide, referring to a now well-known Des Moines watering hole, just before one of the day's news conferences began.

Earthquake aside, the state of New Hampshire had already begun to brace for its week in the political limelight. On Elm Street in downtown Manchester, regular passersby who have frequently been accosted by supporters of political extremist and perennial candidate Lyndon H. LaRouche Jr., have taken to wearing hand-lettered signs that read: "I am a Registered Voter."

At the New Hampshire Democratic Party headquarters, party chairman Joseph Grandmaison has been fretting that there will be so many Secret Service motorcades traversing his tiny state this week that other traffic will come to a standstill.

For some New Hampshire citizens, the return of the presidential campaign is like the return of spring. "I've done this for candidates since I was born," said Toni Peabody, who is married to former Massachusetts governor and Johnson administration appointee Endicott Peabody. Toni Peabody, who now lives in New Hampshire, had removed her leather boots to rub life back into her chilled toes as she waited for Simon to arrive. A few weeks ago, she bought three dozen umbrellas because the rain-repellent fabric was printed with bow ties, a Simon trademark.

And DiVenuti, who has seen candidates come and go from his gift shop doorway for months, judges a candidate by whether he stops in to say "Hello." Gephardt and Robertson have.

"We never got to see George Bush," he said. "Maybe now after Iowa, he'll come and talk to the common folk."