President Obama phoned into a breakfast meeting of African American religious leaders Friday, urging a final push to get out the vote for Sen. Arlen Specter in Tuesday's Democratic primary.

Later, the Black Clergy of Philadelphia & Vicinity, Gov. Rendell, Mayor Nutter, and District Attorney Seth Williams all reiterated during a news conference their strong support for Specter, who is in a tight battle with Rep. Joe Sestak for the party's nomination.

Specter, 80, is seeking a sixth six-year term in the Senate, this year as a Democrat, having left the Republican Party last year because his decisive vote for Obama's $787 billion stimulus bill caused his standing in the GOP to plummet.

Rendell said he was offended by a Sestak campaign ad that says Specter switched parties "to save one job . . . his." The ad's near-constant airing over the last week has coincided with Sestak's rise in the polls.

"He wasn't thinking about saving his job," Rendell said of Specter. "He was risking his job."

More than 20,000 people in Pennsylvania are working because of the stimulus bill, Rendell said.

"This claim of opportunism is outlandish in the context that I had a clear path to reelection if I had not voted for the stimulus package," Specter said. He said the vote was a matter of principle to "avoid a 1929-style Depression."

Sestak, 58, a second-term House member from Delaware County, also campaigned in Philadelphia yesterday, making 11 stops in the city.

"This election is a referendum on how broken Washington is, and Sen. Specter is a poster child for that," Sestak said, after shaking hands at lunchtime in LOVE Park. He said the country might not have needed the stimulus if Specter had not helped enact President George W. Bush's economic policies.

Analysts and political strategists say Specter needs a big voter turnout in Philadelphia, especially of black Democrats, to survive. Specter said he was spending "lots and lots" of street money to pay election-day workers.

The call from the president was closed to the media, but people who were in the room said Obama told the group he needed Specter "on my team."