OLYMPIA — Opponents of the anti-gas-tax measure, Initiative 912, aren't shy about saying their situation seems pretty desperate.

Gas prices continue to surge. A recent campaign poll of voters, largely paid for by big business, found most people want to repeal the 9.5-cent-a-gallon gas tax the Legislature passed earlier this year. In fact, the more voters learn about the initiative, the more they like it.

For the coalition fighting the measure — including business, labor and environmentalists — "that's not good news," said Clifford Traisman, a lobbyist for the Washington Environmental Council, who's helping organize a campaign to defeat I-912. "We are the underdog."

Traisman and other members of the opposition group, Keep Washington Rolling, say their best shot at turning things around is to run an unconventional campaign that eschews traditional tactics. In particular, they say, you won't see prominent politicians on the air urging people to vote no on I-912.

Instead, the campaign has hired experts to develop a strategy that combines targeted mailings with a smaller number of savvy commercials.

"The hope is that if we can do a campaign that's smart and strategic, and we can raise enough money, it's not insurmountable," Traisman said. "We can win this race."

Brett Bader, spokesman for I-912, doesn't buy the underdog bit. "They've got all the money, and all the power elite's in Olympia. It's hard to see them as the underdog," he said.

Still, Bader portrays his campaign as a political tsunami, with 14,000 volunteers across the state and more signing up every day. The group was able to gather more than 420,000 signatures in 32 days to put the measure on the November ballot.

"I'd rather be us than them," he said.

I-912 opponents say they've learned their lesson from past failures, such as Referendum 51, a measure that would have increased the state gas tax by 9 cents to fund road improvements. It lost badly in 2002, even after its supporters spent millions on television and radio ads.

Just mentioning Referendum 51 makes people who were involved in that effort cringe.

"You can't do it over again," said Duke Schaub, a lobbyist for the Associated General Contractors who is helping organize opposition to I-912. "We spent $4 million plus, and we got killed."

In hindsight, the Referendum 51 campaign relied too heavily on television commercials in major markets that repeated the same message over and over to a broad audience, people involved with that campaign say.

Keep Washington Rolling is holding focus groups soon to refine its ideas, but it plans to rely heavily on targeted mailings with specific information about road projects it contends would be put on hold if the gas-tax increase is repealed.

The group points to successful efforts in San Diego and Denver last year as examples of the type of campaign it hopes to run in Washington.

The Proposition A campaign in San Diego convinced a supermajority of voters, 67 percent, to renew a half-penny sales tax for an additional 40 years to pay for $14 billion in transportation projects.

"They transmitted a ton of retail politics. They held town meetings up the ying yang and they did a lot of targeted mail," said Carl Luna, a political-science professor at Mesa College in San Diego.

"They were able to show neighborhood by neighborhood ... what the community would get. That made people happy. It wasn't the abstraction of 'we're going to build a new road somewhere,' " Luna said.

In Denver, the FasTracks campaign succeeded in passing a $4.7 billion tax package last year to build a light-rail and commuter-rail system and expand bus service.

As in San Diego, Denver made heavy use of targeted mailings.

"The direct-mail pieces were custom-made for audiences," said Tom Clark, executive vice president of the Metro Denver Economic Development Corp. Clark served on the campaign steering committee.

"Instead of having a one-size-fits-all message, they had some directed pieces to areas where they needed to firm up support and into areas where they needed a certain percentage of votes that tended to be anti-mass transit. They targeted their voters very carefully and went after them with direct mail."

Without that type of effort, Clark said, the ballot measure "would have been smoked. This is the West."

I-912 opponents are getting help from a Denver firm that helped run the FasTracks campaign. Keep Washington Rolling hopes to raise more than $2 million for its effort, which would still be less than half of what was spent trying to pass Referendum 51. The business community apparently doesn't have the stomach to spend that much money this time.

The campaign, in its polling, found that former Republican gubernatorial candidate Dino Rossi could have a significant impact on how people vote if he endorsed or opposed I-912. Rossi said recently he has no position.

Keep Washington Rolling has tested various messages to see how they'll fly with voters. You can expect to hear a lot in the coming weeks about projects in your area that won't be built if I-912 passes and how much more money it would cost to complete the same road projects in the future if voters pass the measure.

Gov. Christine Gregoire is expected to sound similar themes when she speaks, but don't expect to see her on television. Polls show voters are turned off by commercials featuring politicians. They prefer to see firefighters and engineers.

"As governor and as the leader of this state, [Gregoire] has the responsibility to talk about what's best for the state," Traisman said. "I think that will be helpful. But will she be doing 30-second spots saying, 'Hi, I'm Chris Gregoire and I urge you to vote no on Tuesday'? Absolutely not."

Andrew Garber: 360-943-9882 or agarber@seattletimes.com