But one person with a different view is John F. Street.
Milton Street's younger brother and Nutter's Democratic predecessor in office has been questioning Nutter's leadership on many issues, including education, and said the voter support his brother had received was "not discouraging" as he weighed challenging Nutter in the fall election.
Now a registered independent, John Street said in an e-mail Wednesday that he would conduct "an options review" before making any decision.
Of that possibility, Nutter said at his victory celebration Tuesday night: "We'll see what happens."
Beyond John Street, several political observers and former elected officials said that while Nutter should not be overly concerned, since he carried 76 percent of the vote, he should pay close attention to the support he did not get.
"I don't think that you should dismiss the Street name as if it does not mean anything and dismiss Milton as if he does not mean anything," said W. Wilson Goode Sr., mayor from 1984 to 1992.
Noting Milton Street's decades-long political activism and election to the state House and Senate, Goode said, "That would be a mistake and gross disrespect to the people who supported him and to his contributions."
Calling Nutter "a concerned individual," Goode said he expected him "to ask the question, 'Is there something I need to do to reach out to some of those people who voted for Milton?' "
Turnout in the mayoral primary was 17.6 percent - higher than the percentage when John Street ran for reelection in 2003 or when Ed Rendell sought a second term in 1995. Neither Street nor Rendell faced a primary opponent.
Milton Street emerged as a Nutter rival in February. He built his campaign around what he called the "don't counts" - former inmates, the mentally ill, and poor people in general. He won at least 40 percent of the vote in seven primarily African American North Philadelphia wards that are home to many of the people he spoke about.
"The mayor has an opportunity to reach out and see why 24 percent of the voters decided to go with an individual who, although he has name recognition, just came out of prison and owes taxes and didn't have a dollar in his bank account," former at-large City Councilman Juan Ramos said.
Milton Street spent 26 months in prison for three misdemeanor counts of failure to file a tax return, for the years 2002, 2003, and 2004. His tax debt includes nearly $400,000 owed to the City of Philadelphia.
"I think all elected officials once an election is over take a look and see what the other side did," Ramos added.
In part, Tuesday's results seem to support several polls in which Nutter's approval ratings were higher among white residents than blacks and higher-income residents than lower-income.
"If you are the mayor and his people, you have to wonder: Where is the disconnect? What am I not doing?" Philadelphia political consultant Larry Ceisler said, noting the votes for Milton Street. "If you are going to govern effectively in a city that is plurality African American and you are an African American mayor, you have to find out why you are not pleasing a particular segment."
To be sure, Nutter won the majority of votes in each of the 66 wards.
Sheila Simmons, his campaign spokeswoman, declined to talk about whether the campaign would assess the results or do postprimary polling.
She reiterated Nutter's belief that voters are angry and often express that anger by taking aim at incumbent mayors and governors.
"We know when the nation's finances are tough, and when the city's and state's finances are tough, that it often hits African Americans, who are a vulnerable population, harder than other populations," Simmons said. "I think that is part of what was reflected" in the election.
"Certainly we hope the economic picture is going to improve," she said. "It takes a while for that to be felt at the ground level . . . but we certainly hope that will be reflected in the months to come."
Contact staff writer Marcia Gelbart at 215-854-2338 or firstname.lastname@example.org.
Inquirer staff writer Jeff Shields contributed to this article.