"In Philadelphia, our public safety, poverty reduction, health, and economic development all start with education," he said.
Nutter, a Democrat, referenced Republican presidential nominee Mitt Romney's visit to a West Philadelphia charter school in May, when Romney suggested class size may not matter for student achievement. Romney said that when he was governor of Massachusetts, his administration analyzed test scores and found no correlation: "So just getting smaller classrooms didn't seem to be the key."
Nutter said that shows "Romney doesn't get it."
"If our teachers can't give our children the attention they need, that doesn't matter? If our students spend the day on their feet, or the floor, because there aren't enough desks in a crowded classroom, that doesn't matter?" Nutter asked.
As governor, Romney "failed his students," Nutter charged, and would do the same thing as president.
Romney has not released a budget with specifics on education, but Democrats contend the broad overview of his budgetary philosophy - which maintains spending on Social Security and avoids tax cuts - would inevitably lead to education cuts.
A spokesman for the Republican National Committee, Tedd Kwong, noted Philadelphia's 11.6 percent July unemployment rate. Pennsylvanians "have had enough of Democrats pointing fingers and casting blame," Kwong said.
Nutter peppered his speech with Philadelphia references and reminisced about growing up in West Philly.
"When I shoveled the sidewalk, my parents didn't let me stop with our house," he said. "They told me to keep shoveling all the way to the corner. I had a responsibility to my community."
The mayor then turned that into an endorsement of Obama, who "knows coming together as a nation starts by coming together as neighbors."
Nutter concluded with a high-volume call to fire up the crowd: "Whose values do you want in the Oval Office? Well I know who I want, I know who Philly wants, I know who Pennsylvania wants, and I know who the middle class needs: President Barack Obama."
Earlier Thursday on MSNBC's Daily Rundown, Nutter suggested during the "Shameless Plug" segment that he would like to see the next Democratic convention in Philadelphia.
"When you want to talk about 2016, you might want to think about Philadelphia 2016," Nutter said.
Asked later about that possibility, Sen. Bob Casey Jr. (D., Pa.) said: "That'd be great."
U.S. Rep. Bob Brady said Thursday that he had talked to Nutter about seeking the Democratic convention in 2016 and thinks the city could have a strong shot if local leaders press for it. "Let's keep on pushing," Brady said. "I will talk to the mayor when he gets back."
Contact Matt Katz at 609-217-8355 or firstname.lastname@example.org, or follow on Twitter @mattkatz00.
Inquirer staff writer Bob Warner contributed to this article.