On Jan. 2, when Mayor Nutter begins his second term with Darrell L. Clarke likely presiding over Council, the entire city will have a stake in whether the two can build a relationship - or at least work together without antagonizing each other.

If the past is any indication, they have a long road to transform their arranged marriage into a happy union.

This spring, when Nutter and Clarke were backing competing ideas to fill a huge shortfall in the school district's budget, their interactions were "at best, awkward," said Councilwoman Blondell Reynolds Brown.

"They had to build trust with each other," she said. "Because of that lack of trust, it made it much more difficult for the mayor to see what was doable and what wasn't."

Nutter was never able to get enough support for his soda-tax proposal, and Council passed a real estate tax hike instead, with Clarke's backing.

This fall, as candidates were lining up votes to succeed retiring Council President Anna C. Verna, Nutter lobbied hard for an alternative to Clarke - first Councilwoman Marian B. Tasco and then Councilman James F. Kenney.

So far, Clarke and Nutter have declined to talk about how they plan to bridge their differences. Both sides demurred again last week, noting that Clarke's ascendancy is not yet official - he has pledges from more than a dozen of the 17 Council members, but they have yet to take a vote.

"They don't have a term Council president-elect," Clarke joked. "I checked."

The relationship between Council president and mayor is a crucial one. Each is dependent on the other for moving their agendas, and they can work in concert or frustrate each other's efforts.

The president controls the flow of legislation, while the mayor wields the veto pen.

Members who have spoken to both said they were optimistic. Councilman Curtis Jones, who is in line to become majority leader, said Nutter "had his big-boy pants on."

"The translation is he's a mature leader who understands you have wins and losses," said Jones, a frequent Nutter ally. "I can't speak to what issues they have between them, but I actually believe they're going to make a great pair."

Brown, another Nutter ally who is set to become majority whip, also was hopeful for a good relationship. But she cautioned that she had spoken to both about their agendas and "the honest answer is I don't see a connect yet."

The problem, she said, is they have almost no history of working together.

"I can't think of any instance where the two of them have worked closely, every step of the way, to get major legislation passed," she said. "There's where someone's mettle gets tested, where you can see how a person works."

Councilman Bill Green, who backed Clarke and often clashes with Nutter, said Council and Nutter lack a "shared vision . . . because none has been put forth by the administration."

"What we're missing is the grand plan," he said. "I think the mayor would do himself a world of good to either show it or come up with one."

So far, no one has identified a specific point where Nutter and Clarke would have clashed severely enough to become enemies. The only clear pivot between the two remains former Mayor John F. Street.

Clarke was a Street protege, working nearly two decades in Street's Council office and then assuming Street's seat when he was elected mayor.

Nutter and Street long have been heated rivals, with Nutter running for mayor in 2007 as the anti-Street candidate.

"Nutter has that, if you're with Street you're against Nutter," said Phil Goldsmith, who served as managing director under Street. "I don't think he understands there's subtleties there. I think it's personal."

People close to Nutter and Clarke describe them as having diverging styles and worldviews. Nutter, a crusader against corruption, often has an aversion to playing the kind of City Hall politics that marked Street's administration.

Clarke, on the other hand, is more willing to be "transactional." The term is not meant to have a negative connotation. Rather, it refers to the compromises often made to achieve policy goals.

"The question is, can the mayor allow Darrell and others to be successful, to be successful himself?" Green said. "Can he be transactional? Can he be willing to do politics to be successful?"

Green and others predicted that Clarke would be "good for the mayor," because he would force Nutter into more dialogue and deal-making with Council.

Or, as Jones phrased it, "The mayor, in order to be transformational, has to be transactional." If the two can reach a detente, Clarke could be a great asset.

"What Darrell will be able to do, if the mayor can get Darrell on board, is get things through Council," Green said. "He can get votes."

The best reason for Nutter and Clarke to work together may be a simple a lack of alternatives. Each may have different ideas, colleagues say, but both want to improve the city.

"I think the mayor, if he wants to be successful, has no choice - and I think the same for Clarke," Goldsmith said. "I'm sure they can find much to agree about."

Clarke often is described as a pragmatic politician, low-key and even-tempered - hardly a clone of the more mercurial Street.

As for Nutter, Brown noted that he came to an agreement last month to slash the city's despised business-privilege tax. The legislation was cosponsored by Green, one of the mayor's least-favorite Council members.

"He was able to put that aside and focus on the centerpiece of that legislation," Brown said. "That signals to me that the mayor realizes we can get a lot more done if we all pull together."

If Nutter and Clarke don't come together, the mayor is likely to spend his second term much as Street did - searching for the minimum number of votes to support a veto.

That would force Clarke and the rest of Council to negotiate with him.

"That, by itself," Goldsmith said, "will be transactional."