Wanted: Chief executive for racially diverse urban city. Boasts vibrant Center City, historical district. Rich in academic, medical, and cultural institutions. Financially challenged with modest tax base, high social-service costs, underfunded pension system, and tottering public school system. High crime, unemployment, and poverty rates plague many neighborhoods, while gentrification is rampant in others. Sports teams currently stink. Need to work with strong unions, assertive City Council, and nagging press.

Phil Goldsmith

has been managing director of Philadelphia and chief executive officer of the Philadelphia School District

The skills of being mayor are different from those needed to run for mayor. Campaigning and governing are like courtship and marriage. In courtship you wow the other person; in marriage you acknowledge differences and work on building a stronger relationship.

The objective of campaigning is to get one more vote than the person in second place. The objective of governing is to solve problems in order to make Philadelphia a better place to live, work, and visit.

The City Charter has meager requirements for mayoral applicants. Be at least 25 years of age and a city resident for "three preceding years." No drug test. No standardized exam on civics. Just collect enough signatures on a nominating petition to qualify for the ballot.

However, to be an effective mayor requires the skills of both a good manager and a good politician.

My views have largely been shaped by working closely with two mayors and observing their strengths and weaknesses, as well as their successes and failures.

In 1979, I joined the mayoral campaign of William J. Green - the father of the former School Reform Commission chairman. I developed policy papers, served as press spokesman, helped prepare him for debates, and traveled much of the city with him as he visited wards, spoke to different interest groups, and raised money.

When Green won, I joined the administration and witnessed the transformation of Candidate Green to Mayor Green. The issues he talked about on the campaign were just that - talk. Once in City Hall, he was greeted with a huge budget deficit and labor contracts that needed to be negotiated. There were also people to be hired - and fired.

To start, police and firefighters were laid off, a hard line was taken against all the city unions, a stringent deadly-force policy for the police was instituted, and the Whitman Park housing project was desegregated.

Police and firefighters circled City Hall in protest; many folks in South Philadelphia didn't like his Whitman Park decision, and unions balked at the mayor's tough stance.

The lesson? Anyone running for mayor who needs to be loved by everyone should search for a different job. To paraphrase Abe Lincoln, you can please all of the people some of the time, some of the people all of the time, but not all of the people all of the time.

Tough decisions demand a tough hide.

Unlike a legislator, who can pick and choose the issues he or she wants to tackle, mayors find swarms of problems buzzing around their desk. Mayors can't simply pick the easy or popular ones. They must be able to discern - or prioritize - which ones need their personal attention, which can be delegated, and which will fade with time. A mayor must separate the wheat from the chaff.

An effective mayor must have the confidence to hire the best people and then let them do their jobs. Former Mayor Ed Rendell exemplified that by having David L. Cohen as his chief of staff.

Good mayors must have a sense of purpose, a commitment to something larger than themselves - a vision. It becomes a mayor's North Star, something that guides one's agenda and actions. The mission of Mayor John F. Street, for whom I was managing director, was to revitalize city neighborhoods, forgotten in the shadows of a growing Center City's towering buildings.

But having a mission, establishing priorities, appointing good people, and letting them do their jobs are just the preliminaries. Now the hard work begins.

Mayors are not kings, though they might believe and act otherwise. They are the leaders of one of three branches of local government. To accomplish many of their goals, mayors must be able to work with others. Rendell formed an important alliance with then-Council President Street - an odd couple, to be sure. But it was a relationship that served both men well. Rendell achieved much of his legislative priorities, and Street became the next mayor.

A mayor needs to make deals; it's the currency of governing. But mayors need a strong ethical core to ensure they don't step over the line of probity.

And regardless of how much mayors want to ignore those nagging questions from the media, they do so at their own peril. Street had a prickly, if not hostile, relationship with the media. As a result, rather than give him the benefit of the doubt, the media were often suspicious of his motives.

Mayor Nutter, on the other hand, has skillfully used the media in governing.

A mayor must be disciplined but also flexible. A well-scheduled day can collapse in a second: a wounded police officer, a fallen firefighter, a terrorist attack, a major snowstorm. The possibilities are endless.

Being mayor is a retail job. There is no bubble to hide under. Mayors should like people, not in the abstract but even when the public gets in their face on Broad Street or gives them advice at a restaurant.

Philadelphia is a blue-collar town. Passion beats stoicism - more Clinton-esque than Obama-esque.

It's 24/7, 365 days a year for four years - often eight. It demands stamina, energy, patience, and tolerance.

A tough, demanding job, to be sure, but a great one for an individual who has the moxie to make a difference - and there is much difference still to be made.