On O'ahu, the issue is a $3.7 billion mass-transit project. On the Big Island, it is the economy and how to replace a popular icon. On Kaua'i, it is about growth and a chance for a new direction after an untimely death.

After a primary season that has been like a slow burn, voters on Saturday will select mayors on three islands and pick their party's finalists for state House and Senate campaigns in the general election in November. Several county council and state Board of Education campaigns will also be decided.

Voter turnout in primaries had steadily fallen over the past decade but moved up slightly in 2006 — to 42.2 percent — because of the U.S. Senate primary between U.S. Sen. Daniel Akaka, D-Hawai'i, and then-U.S. Rep. Ed Case. With no comparable attraction on the ballot this year, political analysts believe it will be the mayoral campaigns that influence turnout.

Although the presidential election has many people talking politics this year, the local races have not produced similar interest, and analysts doubt primary turnout statewide will be substantially higher than 2006. Voter registration is up just 1.8 percent statewide from two years ago, and elections officials predict that about 40 percent of voters who participate in the primary will cast ballots via absentee or walk-in voting before Saturday.

Island-by-island turnout may be higher because of the mayoral campaigns. On the Big Island, for example, voter registration is up 6 percent.

"I think there are some hot races in a number of counties that will bring out people in the primary, so I would expect turnout to be above average," said Rick Castberg, a political science professor at the University of Hawai'i-Hilo.

John Hart, a communications professor at Hawai'i Pacific University, said he does not expect primary turnout to be much different than recent trends.

"I think we have a chance for a big bump in the general. You not only have a presidential election, but you have the Hawai'i connection in the race, which I think is going to get people out to vote," he said of Hawai'i-born U.S. Sen. Barack Obama, the Democrats' presidential nominee, who graduated from Punahou School.

"When someone goes to high school here, I think there is going to be more of a pride factor, and people are going to go out, one way or the other."

DOMINATING ISSUES

On O'ahu in the primary, Mayor Mufi Hannemann was gliding to re-election before UH-Manoa engineer Panos Prevedouros and City Council member Ann Kobayashi entered the race late, mostly to challenge Hannemann's plans for a steel-on-steel rail project. Voters will have a chance in November to have a voice on the project through a ballot question, but the mayoral campaign has served as sort of a proxy for the rail debate and Hannemann's leadership.

With a compressed campaign because of the late filings, other issues — such as the city's response to a growing homeless population, an expensive federal mandate on wastewater treatment and an aging landfill — have largely been submerged.

If Hannemann does not get more than 50 percent of the vote, the threshold for re-election in the primary, the dynamics of the campaign could change quickly and the challenger who survives would likely be seen as a more credible rival come November.

Voter registration on O'ahu is up less than 1 percent over 2006.

On the Big Island, where popular Mayor Harry Kim is leaving office due to term limits, former Kim aide Billy Kenoi and state Sen. Lorraine Inouye, D-1st (Hamakua, S. Hilo), are considered the favorites, although County Council members Angel Pilago and Stacy Higa are also contenders in the eight-candidate field. A downturn in the economy, particularly in tourism and construction, has been an issue for voters, along with improving government relations across the island when the center of power is in Hilo on the east side.

"You've got gender and age and education and experience and the whole thing. So that makes it quite interesting," Castberg said of the candidates.

On Kaua'i, where the death of Mayor Bryan Baptiste in June created an unexpected vacancy, Council members JoAnn Yukimura and Mel Rapozo, parks and recreation director Bernard Carvalho and school computer technician Rolf Bieber are trying to replace him. While the economy and improvements to city services have been issues, the pace of new development and whether to welcome back the Hawaii Superferry, which was blocked by protesters last year, have also been themes.

Voter registration is up 2.7 percent on Kaua'i.

RACES TO WATCH

The primary also will break down the candidates for state House and Senate in November. With Obama the presidential nominee, Democrats are optimistic that higher voter turnout will help them hold the seats at the Legislature they picked up in 2004 and 2006. A wave of new Democratic voters for Obama could also help the majority party pick up additional seats.

But because the party has to defend so many seats, most analysts predict Democrats could lose two seats in the House to Republicans but gain one seat in the Senate in November. Democrats now have a 44-7 majority in the House and a 21-4 majority in the Senate.

Overall, there are five open House seats and two open Senate seats, and about 20 House and Senate seats are considered by analysts to be competitive.

"We're very excited about the candidates that we're presenting to the people of Hawai'i this year," said Willes Lee, the state GOP chairman, who believes Republicans may pick up four House seats and break even in the Senate.

Brian Schatz, the chairman of the Democratic Party of Hawai'i, said Democrats would still consider it a good year even if they end up dropping a few House seats. "Because we have 44 seats (in the House), we're going to have to play more defense than offense," he said.

Among the more interesting primary campaigns to watch: