Honolulu City Councilman Charles Djou unleashed a new television advertisement slamming former congressman Ed Case last weekend, his closing argument against his leading rival in the special election for Congress.

In a traditional election, the ad would have hit with maximum impact, since voters often pay the most attention in the final days before they cast ballots. But the winner-take-all special election in urban Honolulu's 1st Congressional District is not traditional.

By the time the ad was in heavy rotation, two-thirds of likely voters had already mailed back their ballots. There was less risk, and reward, in going negative.

"It's different," said Djou, a Republican who is leading in public and private polls. "It's a three-week-long Election Day, with no historical data to go on. So a lot of it is guesswork in terms of what motivates someone to turn in a ballot early versus what motivates somebody to turn in their ballot late."

Djou, Case and state Senate President Colleen Hanabusa — the three leading candidates — have had to adapt their campaign tactics in the state's first experiment with an all-mail special election for Congress after two smaller Honolulu City Council special elections last year.

The state Office of Elections will announce the results shortly after 6 p.m. today. Through Thursday, 159,000 voters — or just over 50 percent of the 317,000 eligible — had mailed back or dropped off their ballots.

The voting pattern has been similar to the two City Council elections and the experience in Oregon, which converted to all-mail elections in 1998.

There was a surge in votes shortly after the ballots were mailed out in early May, followed by an ebb, then a final push toward tonight's deadline.

WASTED EFFORTS

Unlike in Oregon, the Office of Elections has not provided the campaigns with the names of voters who have cast ballots. So, over the past few weeks, the campaigns have wasted time and resources reaching out to many people who had already voted.

Case, a Democrat, said his campaign's strategy was to peak just as voters were receiving their ballots.

"We had a very simple rule," he said. "The rule was that Election Day was May 1 and it lasted three weeks. That's really it. There is no other adaptation. Election Day starts when people start voting. And you've got to be with them as long as they're voting."

Case said he does not believe he was at a disadvantage to Djou and Hanabusa, who had larger grassroots operations. Hanabusa, in particular, had extensive help from establishment Democrats and labor unions.

"The candidate and the message are going to trump that every single time," Case said. "You can have the best GOTV (get out the vote) effort, but if the underlying base is not a good one, it's not going to work. Of course, we'll find out shortly what the result was."

Hanabusa and her allies have been trying to drive up voter turnout, knowing that higher turnout in traditionally Democratic urban Honolulu may prevent a Djou victory.

Hanabusa also wants to prepare for her likely duel with Case in the September primary. The winner of the special election will fill out the remaining months of former congressman Neil Abercrombie's term. The winner of the September primary will take on the winner of the special election again in the November general election.

"We're just telling people, if they haven't gotten out to vote yet, to get out to vote," Hanabusa said.

TURNOUT A SURPRISE

Turnout is already higher than the campaigns expected. Just 13.3 percent of registered voters participated in the traditional special election to fill out the remainder of the late U.S. Rep. Patsy Mink's term in 2002. The two City Council special elections last year attracted 41 percent and 45 percent of voters.

While turnout has already exceeded voter participation in a typical primary, it will likely be on the low side compared with a general election. Voter turnout was 66 percent in the 2008 general election — a presidential election year — and a record-low 53 percent in 2006.

In Oregon, vote-by-mail elections have led to greater voter participation.

William Lunch, a political science professor at Oregon State University in Corvallis, Ore., and a political analyst for Oregon Public Broadcasting, said it has also forced campaign strategists to adjust.

"Candidates, and the organizations working with them, could no longer focus as an orchestra might on a crescendo — sort of Beethoven's Eighth, where you get to the point at which all the drums are beating — that's the way it used to work," he said.

Now, he said, one strategist likened campaigning to the movie "Groundhog Day," a fantasy where a television weatherman wakes up to the same day over and over again.

The voting pattern in Oregon has changed over time. While there is still a rush of votes shortly after ballots are mailed out, more voters are holding on to their ballots until just before the deadline.

Lunch and other Oregon political analysts believe that voters have learned from experience and are waiting to see the campaigns fully play out before they make their choices.

ABSENTEE BALLOTS

Tactically, all-mail special elections are similar to the approach campaigns have been taking with absentee voting in traditional elections. Roughly a third of Hawai'i voters have been voting absentee.

Andy Winer, a political strategist and the director of external affairs at the National Oceanic and Atmospheric Administration, believes absentee voter outreach was one of the main reasons U.S. Sen. Daniel Akaka, D-Hawai'i, beat Case in the 2006 primary for U.S. Senate.

"It's not just a one-shot deal. You can't just make a phone call or send one piece of mail to somebody and say 'Vote by mail,' and have them understand that," he said. "It requires a much more focused and concerted get-out-the-vote effort, either by door-to-door, mail or phone calls. It requires multiple contacts and persistent contacts."

Hanabusa, who has been endorsed by Akaka and U.S. Sen. Daniel K. Inouye, D-Hawai'i, has targeted many of the same voters Akaka did in 2006: traditional Democrats, union members, Native Hawaiians and Japanese-Americans.

Hanabusa, however, had the most difficult week of her campaign just as voters were receiving ballots.

The Advertiser published a poll on May 2 showing Hanabusa in third place. A few days later, a private poll and memo prepared for the Democratic National Committee found Hanabusa lagging behind in third and Case with the best chance against Djou.

Hanabusa held a press conference on May 5 to announce that she would not drop out of the race.

Two of the three televised debates also aired that week, so voters tuning in to the campaign for the first time saw Hanabusa against a backdrop of the negative poll numbers.

"All of that was really out of our control," said Eric Hamakawa, Hanabusa's campaign manager. "I think from the media perspective, you guys have got to take a look at whether — if elections are run this way again — whether or not you guys actually do these polls so late in the game. I think it does have a factor in influencing voters."