Campaign spending by winning state Senate candidates increased by an average of more than $5,000 during the latest election cycle, and some of the biggest spenders were incumbents who ran unopposed.

The 13 winners spent more than $1 million in total, or an average of more than $78,000 each, during the four-year period that ended with last month's election, state records show.

Winners spent an average of $73,000 before the 2004 election, but campaigns have been much more expensive in some earlier years.

Senate winners spent an average of more than $96,000 on races that were decided in 1998, when competition was more intense, for example.

The top spender in the latest election was incumbent Sen. Carol Fukunaga, D-11th (Makiki, Pawa'a), who spent more than $180,000 on her campaign over four years — more than twice the average — and won nearly 70 percent of the vote.

Some of Fukunaga's biggest expenditures were for campaign mailings and catering for fundraising events, according to reports filed with the state Campaign Spending Commission.

Fukunaga said that some of her campaign funds went to legislative business, such as refreshments at community meetings or equipment for functions.

She suspects that her mailing costs are also higher than other candidates because her district has the largest number of condominium buildings, which prohibits door-to-door campaigning.

"Almost all of my communication is by direct mail," Fukunaga said. "Probably I have much higher postage and mailing expenditures."

Because postage costs have increased, Fukunaga said that her legislative allowance would not cover the costs to mail her newsletters, so she generally uses campaign funds to mail out those periodic updates.

The lowest spender was unopposed incumbent Sen. Sam Slom, R-8th (Kahala, Hawai'i Kai), who spent less than $14,000 .

Slom said he was surprised that no one challenged him, but that he only accepts campaign contributions during the months immediately before an election, after candidates have filed their candidacy papers.

"I don't like to spend a lot of money on political things, and I certainly don't like to ask people for money," said Slom, who has represented one of O'ahu's most conservative and Republican-leaning districts for a decade.

He said he prefers to interact with constituents at community meetings or when he bumps into them at the supermarket.

"I'm not denigrating the fact that it does cost money to run for office, but I don't think it should cost as much," Slom said.

Three of the top six spenders were unopposed incumbents: Fukunaga; Sen. Brian Taniguchi, D-10th (Manoa, McCully); and Sen. Norman Sakamoto, D-15th (Waimalu, Moanalua, Salt Lake). Another incumbent, Sen. Shan Tsutsui, D-4th (Kahului), faced an opponent only in the primary election.

Incumbents typically raise and spend the most, as their campaigns tend to attract money and remain active during their entire four-year terms, said Honolulu campaign consultant Don Clegg.

"It's anticipated that incumbents are going to stay there, and people who support them want to be looked upon favorably," he said.

It's easier to build up a campaign account by raising money in small amounts during non-election years than to seek big donations later, Clegg said.

"During the last months before an election, everybody is having fundraisers, so there's a lot of competition," he said. "In the 'off' years, you're only competing with charities to raise money."

Incumbents never really know how much opposition they will face until the candidacy filing deadline passes a few months before the election, so it's best to be prepared for a challenge, he said.

Some candidates like to have lots of money on hand to intimidate potential rivals from jumping into a race, Clegg said.

"That's certainly a motivating factor in going out and getting money early," he said.

Few of this year's Senate races generated much excitement, but the cost of campaign mailers, yard signs, giveaway trinkets and other expenses can be substantial even in lukewarm contests, Clegg said.

"If you want to keep in touch with your constituents, of course it costs money," he said.

Conducting polls for various races has made it clear that many voters don't agree ideologically with the candidates they elect, and don't follow their actions closely once they're in office, Clegg said.

But they often support those same candidates because they recognize them, received mailings or giveaway items from them, or saw their campaign signs in their neighborhood.

"A lot of campaign funding is spent to get name recognition," Clegg said.

Reach Johnny Brannon at jbrannon@honoluluadvertiser.com.