Momentum — that nebulous, intangible “it” factor that every politician desperately seeks and every campaign needs to win.

But to define it and, harder yet, to determine who has it, is a tricky business. Nonetheless, Republicans believe the Senate campaign of Rep. George Nethercutt (R-Wash.) has it.

They build a compelling case: Nethercutt has received abundant favorable press since formally kicking off his effort to unseat two-term Sen. Patty Murray (D) last month. His name identification is improving. He has made legislative progress on some key Washington state issues, and big-name Republicans have trooped one after the other out to the Evergreen State to stump and raise money for him.

The biggest GOPer of them all, President Bush, will headline a $1,000 per person buffet dinner for Nethercutt in Spokane on Thursday.

“The president is coming here first because he’s impressed with my campaign’s early momentum,” Nethercutt said in a news release touting the fact that he’ll be the beneficiary of Bush’s first Senate fundraiser this cycle.

But then Monday, Mason-Dixon Polling & Research Inc. released numbers showing Murray’s support at 53 percent and Nethercutt’s at 34 percent.

“He keeps talking about momentum, but his numbers haven’t changed since he entered the race,” said Kirstin Brost, spokeswoman for the Washington State Democrats. “It’s spin backed up by nothing.”

Alex Conant, Nethercutt’s campaign spokesman, says the Congressman is in good shape and that the poll does not debunk the idea that momentum is on his side.

“The fundamentals remain very strong for us in this race,” Conant said. “The president is strong, Murray is weak and where voters know George, we win. We’re feeling very good about it.”

Conant added: “Our emphasis has been on fundraising, building a grassroots organization and building buzz with opinion makers in the state.”

To that end, the Nethercutt campaign has succeeded.

A parade of prominent Republicans, including Vice President Cheney, Sen. Elizabeth Dole (N.C.), Senate Majority Leader Bill Frist (Tenn.) and several Cabinet officials, have attracted big-money donors to fundraisers in both Washingtons, helping Nethercutt stockpile almost $2 million so far.

That is far less than Murray’s nearly $5 million war chest, but neither Democrats nor Republicans doubt that Nethercutt will have all the financial help he needs.

“Republicans have a lot of money to throw around this year,” Brost said. “Nethercutt will have the money he needs, but Patty will have the money she needs to win too.”

As for buzz, Nethercutt has gotten good coverage on a number of issues from local and national media.

For instance, a letter he wrote chiding Major League Baseball for considering partaking in a publicity blitz for the “Spiderman 2” movie won him plaudits from sports and editorial writers on both coasts and got him mentioned in The New York Times and on ESPN.

While the campaign seems to be hitting on all cylinders these days, Republicans concede that Nethercutt needs to make more progress in one key area — building name identification.

“He’s getting lots of good coverage,” said Suzanne Tomlin, spokeswoman for the Washington Republican Party. But “he still has to work on the name recognition angle; the stories are helping with that,” she said.

Conant says the campaign is working hard to ensure that Nethercutt becomes better known.

Nethercutt is the Congressman for most of Eastern Washington, but the majority of voters reside on the other side of the Cascade Mountains in and around Seattle.

“Our name identification is still pretty low in the West but as people turn their attention to this race, support will grow,” Conant said.

Conant pointed to a recent television station poll that showed him leading Murray in Eastern Washington.

Brost disputes the idea that voters will turn to Nethercutt once they learn his name .

“When they get to know him … they aren’t going to vote for him,” Brost said.

For her part, Murray has kept a relatively low campaign profile, preferring to stick to her Senate duties instead of aggressively campaigning.

“She’s taking both seriously,” Murray campaign spokeswoman Alex Glass said. But the campaign kickoff will not happen until the first week of August, Glass said.

Republicans question Murray’s “Rose Garden” strategy.

“They’re sitting on their millions and I think they’re going to be surprised,” said Washington state GOP consultant Jim Keough, who is working for state Sen. Dino Rossi, the likely Republican gubernatorial nominee. “They’re making a tactical error.”

The Mason-Dixon poll reveals that, for now at least, Murray is not hurt by the fact that she is not on television or stumping frequently.

The key to checking the political health of an incumbent is the support number, said Brad Coker, managing director of Mason-Dixon.

“As long as she’s over 50 percent, she’s fine,” he said.

Those results counter a KING-TV/KHQ-TV poll, conducted June 1-3 by Survey USA, that Nethercutt’s campaign seized to show momentum was with their candidate.

That poll showed Murray with less than 50 percent support.

However, Survey USA’s results are widely regarded as less credible than those of many firms because of the automated polling method it uses.

Even so, “that poll still had Murray cleaning his clock,” Brost said.

While it may be impossible to pinpoint which direction momentum in this race is running right now, Nethercutt is regarded as one of this cycle’s most credible Republican Senate challengers, and this race is being closely watched by national leaders from both parties. Once on par with the Wisconsin and California Senate races, most national Republicans now believe that their prospects for upsetting a Democratic incumbent are greater in Washington than in the other two states.

Nethercutt knocked off then-House Speaker Tom Foley (D) to win election to his 5th district seat in 1994 and earned himself the nickname of “the giant killer.”

“Nethercutt has been in tough races before, that’s what made him such an attractive candidate to us,” said Dan Allen, spokesman for the National Republican Senatorial Committee.

“Murray,” he added, “is no Speaker of the House.”