Although he’s been out of office for a decade, Ben Cayetano is hardly an unknown commodity in Hawaii politics: 28 years in elected office, the last eight as governor, and all three decades of public service as a card-carrying Demo­crat.

So he chuckles at the notion that as he comes out of retirement to seek another office — even in a nonpartisan race — he is winning a lot of support among Republicans.

"This is a nonpartisan race, and some of the people who support me, they wouldn’t agree with me on anything else — Republicans, Demo­crats," Caye­tano said in a recent interview. "But the understanding is that this is not an ideological election.

"On this particular issue there’s a lot of people who agree with me."

The issue, of course, is rail.

It is the largest public works project in state history and promises to bring in $1.55 billion in federal funds. Ground has been broken in Kapolei. Millions of dollars in contracts have been awarded, construction has begun — and Caye­tano wants to bring it all to a screeching halt.

That puts him squarely at odds with Mayor Peter Carlisle and former city Managing Director Kirk Caldwell in the race for the top job at Hono­lulu Hale.

To state Sen. Sam Slom, the only GOP member of the state Senate, Caye­tano is the only one of the three who "gets it."

"He’s the only one that understands the full fiscal implications of what’s happening with the city," said Slom (R, Diamond Head-Hawaii Kai). "I’ve watched all of the so-called debates, and while the other candidates have tried to paint Caye­tano as a single-issue candidate — the rail — he said from the very beginning and he said in every appearance in the media that it’s about maintaining the infrastructure of the city."

Slom isn’t the only Republican supporting Caye­tano. A Star-Advertiser/Hawaii News Now poll in January showed the two-term Demo­cratic governor with 47 percent support from those who usually vote Republican.

"It shows two things," Slom says. "That there are strange bedfellows in politics and, No. 2, that everything in the world is cyclical. I’ve known Ben for 40 years. We’ve had our ups and downs — mostly downs — but I’ve always respected him.

"You always know exactly where he stands."

But Cayetano’s stance has changed from just two years ago, when he supported Carlisle in his special-election victory for mayor.

As the rail project progressed, Cayetano said, he became increasingly unhappy with the way it was being handled, from numerous public relations contracts and inflated forecasts of future job growth to costly change orders and the city quietly suspending its self-imposed 20 percent debt ceiling. Last year he joined a lawsuit by rail opponents seeking to stop the project on the grounds that the environmental impact statement was flawed.

"I’m open to light rail," he says. "But in this case it’s this particular rail that I’m opposed to. The process that it went through was so terrible."

As 2012 approached, Cayetano’s vocal opposition began attracting anti-rail forces seeking a viable candidate to put up against Carlisle and Caldwell.

"Pretty soon the thing kind of took on a life of its own," Caye­tano says. "One day my wife just told me, ‘You know what? You’re so bothered by all this, why don’t you run?’ I talked it over with her, then we agreed, and so I’m running.

"If somebody else ran and I think that person had a chance, I would not be running."

Now he finds himself the front-runner in the race.

His focus has been on upgrading and rebuilding the city’s crumbling infrastructure — filling potholes, paving roads, rebuilding sewer lines and other such projects — instead of building a rail system that he says is likely to come in over budget and destroy Hono­lulu’s scenic views.

"I don’t have any doubts that he’s fully capable of it," said state Rep. Gil Keith-Agaran (D, Kahu­lui-Paia), a former Caye­tano Cabinet member. "He was always interested in transportation issues and basic infrastructure issues, and that’s what you need to do at the county level.

"A lot of his administrative skills will translate pretty well to the city government, and the reason I say that is that he’s going to find good people to run those departments, and that’s the key part. He’s going to provide leadership, and as you can see, he’s never afraid to tell people what he thinks."

Critics and his opponents have assailed his lack of details for an option, should he win and succeed at killing the rail project.

Cayetano says he would go back to a 2003 environmental impact study by Parsons Brinckerhoff that touted the benefits of a less expensive bus rapid transit system. But questions remain about how the system would operate: Which lanes it would use? Would it require elevated lanes? Would it take up parking on downtown streets?

"The basic concept is in that 2003 EIS," he says. "The regional part, in other words, from Kapolei and all of that to downtown, is pretty much set. We can do that."

Determining how the system would operate as it gets into town would require more study of various proposals, such as restricting parking on some streets or using buses on shoulder lanes. "We can look at new ideas," he says.

As the campaign has progressed, Caye­tano has found himself the target of what he calls a smear campaign by pro-rail interests who he says stand to lose hundreds of millions in contracts if the project dies.

This mayoral campaign reminds him of his 1998 re-election bid against Linda Lingle, which Caye­tano won by 1.3 percentage points.

"The Republicans were very well organized, and we had a formidable candidate on the other side," he says. "There were times there when I felt a little down, but in the end, maybe it’s me, but people who know me know that I’m a fighter. I don’t give up.

"This one here, with all the big guys on the other side, I kind of relish the challenge. I want to see if they can beat us."

Should he win, either in the Aug. 11 primary or the November general election, Caye­tano would take office at age 72, with his 73rd birthday coming in November. Despite his age, Caye­tano says, he feels energized at the prospect of taking over city government.

"Because I believe in what I’m doing, and … it’s personal," he says. "I’m still idealistic. I think about the future of this city and what we’re going to leave to our kids. That’s what I think about, and it really pisses me off every time I think about it."

Cayetano says he has no aspirations for higher office, but whether he would seek a second term would depend on what gets accomplished.

"I’ll go one term at a time," he says. "If I can’t do the job in one term, I’ll run for re-election and try to finish it.

"A lot of the problems that I think the city faces are really big, huge problems and may require two terms and, really, some hard work. People are going to have to make sacrifices because they’ve neglected this thing so much — the infrastructure — that it’s going to cost."