"Health care now!" boisterous Obama supporters at 12th and Arch Streets chanted while Obama headlined a fund-raiser inside the center for Sen. Arlen Specter.
"USA! USA! USA!" the smaller crowd of opponents shouted from the opposite corner.
Sometimes the verbal jousting got a bit petty.
"Pigs!" someone on the conservative corner shouted at the liberals, referring to the massive rise in debt-financed government spending.
"Losers! We won!" a supporter of the president shouted back, referring to last year's election.
Other interests were represented at the demonstration.
"UFO Disclosure Now," read the sign of one man with his own conspiratorial (or comically mocking) agenda.
In the meantime, President Obama swept into Philadelphia yesterday to help newly minted Democratic Sen. Arlen Specter raise nearly $2.5 million for his reelection campaign, inserting the White House directly into a primary battle.
"I'm going to need all of you to redouble your efforts in the months to come to fight for Arlen, because he's fighting for you, and he's fighting for what's right," Obama told about 200 big-ticket donors at a private dinner at the Convention Center.
"It's not easy, because we live in a polarized environment, and politics has become sport," Obama said, "and it's hard to sustain complex arguments about why we have to make choices that don't always seem real attractive on the surface." Specter's crucial vote for the stimulus package, he added, helped pull the economy from the brink.
Specter, speaking before Obama, praised the president for attacking problems from the economy to health care and global warming, and he mused about the political mood of the country.
"It's a very curious election - there's an enormous amount of anger out there," Specter said. "Nobody is safe."
News agencies also report, the latest confusion over the Employee Free Choice Act highlights the difficulty the proposal is causing for congressional Democrats, labor leaders and President Barack Obama.
The act would make it easier for unions to organize workers and win initial labor contracts through binding arbitration, which they say would help to counter what they call employer intimidation. It's a top legislative priority for union leaders, but is strongly opposed by business groups, which say the current proposal would allow unions to bypass secret ballot elections and stall contract talks until federal arbitrators impose settlements.
The measure has failed to win the 60 votes needed to overcome a filibuster in the Senate. The bill faces opposition from Republicans and a group of Democrats from more conservative states where the measure is viewed as a threat to jobs.