He has overseen three years of elections-office troubles and a $40 million computer fiasco. His policies generated rural rage over land-use rules and suburban angst about a roving homeless camp. He veered leftward by stumping for a state income tax and gay marriage during last year's failed gubernatorial bid.

And on Saturday, Republican Metropolitan King County Councilman David Irons announced his challenge to Sims, saying voters are ready for a change. Republicans have brandished polls they say show Sims is vulnerable.

"People are really, really tired of bad government. They want a change and they deserve a change," said Michael Young, chairman of the King County Republican Party.

Yet for all the bold talk, Sims remains a daunting incumbent. He's known as a gregarious and charismatic politician and he already has raised $211,000 for his re-election. Some Republicans concede they'll have a tough time unseating him and several potential challengers have shied away from the race.

Sims says his accomplishments as county executive outweigh any blemishes.

"I think people have looked and found out that I am doing just fine. I am well-liked and well-respected, and the county government is well-respected," he said.

THOMAS JAMES HURST / THE SEATTLE TIMES, 2004 "I am well-liked and well-respected," says King County Executive Ron Sims, "and the county government is well-respected."

For example, Sims cited his persistence on Sound Transit's light-rail project, which is finally beginning construction after years of delay. The county also has reduced jail costs and maintained many core services despite slashing $135 million from its budget in recent years, he said.

Though he twice has sought higher office — running for U.S. Senate in 1994 and governor last year — Sims said he had no intention of seeking another job if re-elected.

Politically, Sims' advantage begins with the 'D' that will appear next to his name on the ballot. No Republican running for statewide office carried King County in last year's election. Rob McKenna did best, garnering 46 percent of the county vote in his successful attorney general campaign.

The last Republican to hold the county executive's seat was Tim Hill, a Seattle moderate who was defeated by Gary Locke in 1993.

Sims, 56, served on the county council 11 years before succeeding Locke as county executive in 1997. In his previous two campaigns, Sims has easily dispatched his Republican opponents. Four years ago, he took 61 percent of the vote against Republican Santos Contreras, a Kirkland City Councilman.

In addition to the usual core of Democratic Party constituencies, several observers said Sims has reached out to key business leaders, particularly homebuilders, constricting a potential source of campaign money for Republicans.

The Master Builders Association of King and Snohomish Counties recently held a fund-raiser for Sims at its Bellevue headquarters. Sam Anderson, executive officer for the organization, said "we've gotten a lot out of the executive's office" over the past four years.

Sims has aided homebuilders by making it easier to get permits and has eased some growth-management "concurrency" rules that can impede new development, Anderson said.

Bob Wallace, president of Wallace Properties and a prominent Sims endorser, said he sometimes "violently disagrees" with him. He cited, for example, the critical-areas ordinance, which restricts rural property owners from, among other things, clearing native plants on their land. But Wallace said Sims has worked enough with business leaders to earn his backing.

State Rep. Fred Jarrett, R-Mercer Island, who had considered a run, said he was dissuaded in part because of Sims' business support.

Jarrett and Senate Republican leader Bill Finkbeiner, who also considered running, would have faced a fund-raising disadvantage because of the ban on state lawmakers soliciting campaign cash while the Legislature is in session.

Irons, 52, doesn't have that problem. And he knows county issues, having served on the county council since 2000, representing a large East King County district that stretches from Maple Valley to Sammamish.

Next year, that district will be eliminated as part of an initiative cutting the council to nine members, down from 13. To remain on the council, Irons would have had to run against friend and fellow Republican Kathy Lambert.

Instead, he hopes to convince voters the state's most populous county deserves better management than Sims has delivered.

"Our current management is not getting it done. We've lost the faith and trust in the management of King County. It's not any one thing. This is the death of a thousand cuts," Irons said.

Irons noted that problems with the elections office have been going on for the past three years, and have claimed the jobs of the last couple of elections chiefs. Under Sims' watch, the county also paid more than $40 million for a payroll computer system that had to be scrapped before it was ever finished.

Sims said he has taken responsibility for the computer problem and steadfastly defended his elections office as conducting extremely accurate vote counts. "We are committed to improving," Sims said. "But this wasn't a disaster, I can tell you that."

Irons also represents an area that has seethed over the new land-use restrictions in the Sims-backed critical-areas ordinance.

In November, a parade of dusty pickups and empty horse trailers circled the county courthouse in downtown Seattle, carrying placards like "Ron Sims: Kiss My Grass."

Protesters heckled Sims last month at an Issaquah Democratic Party meeting and recently delivered a "bouquet" of blackberry vines, pansies and purple loosestrife to his house — a reference to the rules that require rural landowners to leave such vegetation untouched on much of their property.

Such "rural rage" has grabbed headlines, but it's not clear how much of a political liability it will prove.

Just 130,000 live in all of rural King County, out of a population of 1.7 million. About 8,500 are affected by the most controversial of the land-use rules, said Rodney McFarland, president of Citizens Alliance for Property Rights.

And the opposition is far from the Central and South Seattle neighborhoods where Sims' political support is strongest. But McFarland said critics of the ordinance have garnered a lot of sympathy and won't be quiet during the election.

"If somebody does something good for you, you tell 10 people. If somebody does something bad to you, you tell 200 people," he said.

Sims also irritated some suburban communities when he cleared the way for the Eastside's first tent city last year, OK'ing a plan to allow the roving homeless camp to occupy county land in Bothell.

Former Republican U.S. Sen. Slade Gorton has agreed to co-chair Irons' campaign. But some questioned whether Irons, who is not known as a polished speaker, can muster enough charisma or political horsepower to beat Sims.

Irons also has received unwanted controversy in previous elections due to his estrangement from his parents and a sister, who opposed his past runs for county council in part because he ousted Councilman Brian Derdowski, a family friend.

Martin Durkan Jr., a lobbyist who arranged polling showing Sims with soft re-election support, said Irons was "not the strongest of the field" of potential challengers. He said former State Supreme Court Justice Phil Talmadge and Port of Seattle Commissioner Bob Edwards polled better. But both have said they won't run.

However, Durkan, who has clashed with Sims on Sound Transit and other issues, said Irons is a credible candidate who could be aided by the long-running controversy over the county's handling of the governor's election.

He also could benefit from lower turnout in Democrat-laden Seattle in an off-year election with few other big races.

"You have to give Sims the edge right now, but it is not the edge he is used to," Durkan said.

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