On Tuesday, Pat Dangillo was on a mission as she marched to the polls at Nebinger Elementary School in the Bella Vista neighborhood: Change Philadelphia.

"This is the only shot we got," said Dangillo, 61, a retired city worker.

Jeff Waters felt similar urgency at West Philadelphia's Pinn Memorial Baptist Church. "It's time for a definite change," said Waters, 39, who has a shoe-shining business.

In all, at least 175,000-odd people agreed things needed to be different in the city. About 62 percent of the votes cast in the Democratic mayoral primary went to the two candidates who crafted their campaigns around challenging the status quo.

Civic leaders and citizens may debate what kind of mandate accrues to former City Councilman Michael Nutter, who won by capturing nearly 37 percent of the vote in a field of five major Democrats.

But it is clear that he and the second-place finisher, businessman Tom Knox, stoked and benefited from a desire for change in an electorate historically averse to it.

Several trends that had been building for at least four years combined to create the political atmosphere that led voters to strike against City Hall corruption and a government many perceived as ineffective at performing tasks ranging from picking up trash to fighting crime:

Corruption. In 2003, an FBI bug was found in Mayor Street's office, disclosing a federal investigation of pay-to-play politics in city contracting. Two dozen convictions resulted. Other incidents kept the issue alive - from former Councilman Rick Mariano's six-year federal prison sentence for selling favors, to this year's indictment of State Sen. Vincent J. Fumo on charges that he used state and nonprofit money for personal and political gain.

(Four years ago, a backlash over discovery of the bug helped Street win reelection; supporters portrayed him as the victim of a Republican-run Justice Department.)

Campaign-finance limits. Reacting to the pay-to-play scandal, Council in 2003 voted to cap donations to candidates at $5,000 from individuals and $20,000 from political committees.

Knox, exempt from the limits under a Supreme Court ruling because he was financing his own campaign, spent millions on a TV ad blitz and by March was raising alarms in the city's political class when he shot into the lead in polls. But when some entrenched Council members tried to roll back the spending limits, public protests caused them to back off - amid fears that voters would punish them.

Anger at political insiders. This tide had state and national origins: After Pennsylvania legislators gave themselves the 2005 middle-of-the-night pay raise, 55 lawmakers went down to defeat in primary and general elections last year. Anti-incumbent sentiment rose higher in November's midterm congressional election, with voters citing Republican scandals as a top reason - along with Iraq - to turn Congress over to Democrats for the first time in 12 years.

"For a half-dozen reasons, people are just angry at the status quo," Neil Oxman, Nutter's media strategist, said Friday. "There's a general unease."

Activist groups. Several have bloomed in the city to push for various reforms, including Philadelphia Forward, which advocates tax cuts and tighter ethics laws, Philly for Change, and Neighborhood Networks. Other groups sprang up to fight the two casinos proposed for the Delaware River waterfront.

"Usually you see these groups go away after a crisis," said Brett Mandel, head of Philadelphia Forward. "We haven't gone away. You can still see the flag of reform planted here and there around town, and that emboldened some people."

Dissatisfaction with Street - and with the city government's overall direction. In every opinion poll in the last year, Street's approval rating hovered at about a quarter of the electorate. And a Temple University poll in March for the Pennsylvania Economy League found a deep mistrust of city government. One finding: 76 percent agreed that "a few big interests" run City Hall for their own benefit.

"A big chunk of what voters were saying is they are disappointed with what Mayor Street has done and excited about someone new taking over," said pollster Michael Hagen, director of Temple's Institute for Public Affairs. "That was really the chord that Nutter struck."

The murder rate. The vote for change might not have happened if not for a dramatic increase in homicides and the perception that city government was at best overwhelmed by the problem, and at worst indifferent.

The violence crisis, analysts say, helped weave together all the strands of discontent.

"The murder rate became the lightning rod for feelings about a lot of things in Philadelphia," Democratic consultant Saul Shorr said. "Do I think pay-to-play or corruption would have been a big deal if there had been a low crime rate? No. They were added to the mix of frustration."

Indeed, government ethics ranked low on the list of voter concerns in polls, with crime on top, followed by schools and the economy. Conventional wisdom said government ethics was too abstract to motivate many voters.

But some saw the link. Knox even put it in a campaign pitch, promising voters that he'd curb City Hall corruption and use the savings to hire 1,000 more police officers.

In a campaign uniquely dominated by forums and debates, Marc Stier, a Temple professor who ran unsuccessfully for an at-large Council seat, said he had heard ethics concerns raised during many forums - on other subjects.

"People connect the fact that pay-to-play and corruption must be why 'there's no money to clean my street or pick up my trash,' or political connections are why 'this neighborhood gets something our neighborhood doesn't,' " Stier said.

Though they had less success in backing Stier and other Council candidates, reform-minded activists are taking heart from what they see as a clear mandate for change, as expressed in the voting for mayor.

"Citizens in Philadelphia have deeply wanted reform for years and years, but we've been told there was no way it was going to happen because the machine was too powerful," said Anne Dicker of Casino Free Philadelphia. "Having people talking about reform, taking it into the open, legitimizes the idea it could really happen."

Contact staff writer Thomas Fitzgerald at 215-854-2718 or tfitzgerald@phillynews.com.