As the Aug. 18 primary approaches, Seattle Mayor Greg Nickels knows many voters dislike him. With seven challengers splitting the anti-incumbent vote, Nickels seems likely to advance. The question the primary will answer is this: What kind of change will Seattle be offered in November?

This should have been a banner summer for Seattle Mayor Greg Nickels.

He was sworn in as president of the U.S. Conference of Mayors. Seattle was named the No. 1 green city in the country by the Natural Resources Defense Council. And Sound Transit’s light-rail line, which Nickels has worked toward for two decades, finally opened.

Yet when Nickels recently rolled out the first television ad of his campaign for a third term, he led with a mea culpa. “As mayor, I’ve made my share of mistakes,” he said, in a voice straining with humility.

He went on to boast of light rail and other accomplishments. But the message was clear: As the Aug. 18 primary approaches, Nickels knows many voters dislike him — poll after poll suggest they want change at City Hall.

With seven challengers splitting the anti-incumbent vote, Nickels seems likely to advance.

The question the primary will answer is this: What kind of change will Seattle be offered in November?

“Do you want a whole new regime — somebody without any ties into the past who will come in with new people, new everything? Or do you want to change some things, but you’re not willing to overturn the boat?” said Blair Butterworth, a political consultant to mayoral candidate and City Councilmember Jan Drago.

One-time Nickels ally

If voters agree with Nickels on most substantive issues, but are simply tired of his style, they’ll find good company in Drago.

Just a few months ago, she scoffed at the idea of running, praising Nickels as a leader with real accomplishments. She initially dismissed public complaints about the December snowstorm, saying she’d gotten around town just fine in a four-wheel-drive car.

But once polls convinced her the mayor was vulnerable, Drago jumped in, abruptly morphing into a loud critic of the city roads department.

On the campaign trail, Drago talks about working more collaboratively with the City Council and regional leaders. Her platform also leans pro-business; Drago says she’ll cut permit costs and work to lower utility rates.

Drago has two big advantages over Nickels’ other rivals. As a council member since 1994, she has been elected citywide four times. She’s also the only woman among the leading candidates and, if elected, would be just the second female mayor in Seattle history, after Bertha Knight Landes, who served a single, two-year term from 1926-27.

Aggressive critic

If voters want more sweeping change, they could go for T-Mobile executive Joe Mallahan.

A first-time candidate, Mallahan grabbed instant attention by putting $200,000 into his campaign. He’s tapped friends and business associates to bring his total to $320,000 as of last week.

As someone who has not been engaged in Seattle politics before, Mallahan is running a classic outsider campaign, arguing city government is “broken.” He’s been one of the most aggressive critics of Nickels’ management and has called for the firing of Seattle Department of Transportation Director Grace Crunican.

But aside from bashing Nickels, Mallahan has struggled to define exactly what he’d do as mayor. His main claim is that he’d use his business acumen to “deliver basic services” more efficiently.

Still, Mallahan seems to have spooked both Nickels and Drago. Both their campaigns have sought to link Mallahan to anti-union actions at T-Mobile. And a Nickels campaign worker has shadowed Mallahan at speaking events to record his speeches.

Anti-tunnel candidate

Of all Nickels’ major rivals, Mike McGinn offers the clearest contrast on a big issue — his outspoken opposition to the proposed $4.2 billion project that would replace the Alaskan Way Viaduct with a tunnel.

McGinn, an attorney and Sierra Club leader, says the tunnel is too expensive and ties the city’s future to polluting cars. He favors tearing the viaduct down and funneling traffic onto surface streets while boosting mass transit.

With other environmental leaders, McGinn opposed a roads-and-transit measure in 2007, arguing that building new highways was a mistake. The measure failed, and a transit-only plan to expand light rail won voter approval last winter.

McGinn also favors more direct city intervention in public schools — including a takeover if necessary. He also says he’d fight to preserve bus service and push for a citywide fiber-optic network.

Former Sonic

Former Sonic James Donaldson, whose name recognition has helped him in early polls, has tried to position himself as a friend of small business.

He seems to have no shortage of ideas — he announced a 134-point agenda last week that calls for everything from keeping libraries open on Sundays to installing video cameras in high-crime areas and cutting the city budget by 10 percent.

But Donaldson’s campaign has been mired in debt and he has struggled to win major endorsements.

Before running for mayor he was not politically active, and skipped voting in eight consecutive elections from 2004 to mid-2007.

Rounding out the field of challengers are three longshot candidates: Elizabeth Campbell, who favors an aerial rebuild of the Alaskan Way Viaduct; Central Area activist Kwame Garrett; and corporate recruiter Norman Sigler.

Amid all the criticism, meanwhile, Nickels has struggled to remind Seattle voters he’s worked on issues dear to their hearts, such as transit, global warming and gay rights. He recently released a “progressive agenda” for the next four years, vowing to oversee the expansion of light rail to the University District “on time and on budget,” build new parks, streetcars and 1,000 electric-car charging stations.

Though Nickels has been stuck in the polls, with only about 25 percent of voters saying they want to re-elect him, he still may have time to turn it around.

“We all forget that the election dramatically changes when it comes down to two people and both of them get scrutinized at a level they haven’t been before,” said John Wyble, a local political consultant not working for any mayoral campaign.

First, though, Nickels has to be one of the top two vote-getters in the primary — something he has not been taking for granted.

In a fundraising letter last week, the mayor sounded a little desperate, complaining of a “negative media filter” and “barrage of negative attacks from my opponents.”

Having already spent most of his $510,000 campaign fund, Nickels pleaded for help to keep his TV ads on the air.

“I don’t have any illusions about this campaign. Just like 2001, I expect it to be tough,” he wrote. “We must do well in the primary to position ourselves for November.”

Jim Brunner: 206-515-5628 or jbrunner@seattletimes.com