PHILADELPHIA -- In a speech before more than a thousand union leaders at the state's AFL-CIO convention today, Sen. Hillary Rodham Clinton again vowed to keep fighting for the Democratic presidential nomination.

"Could you imagine if Rocky Balboa got halfway up those art museum stairs and said, well, that's about far enough?" she said, referring to the famous movie scene filmed just blocks away from her Center City speech.

The comments came as statewide polls show Mr. Obama is chipping away at Mrs. Clinton's one-time large lead in the state.

A Rasmussen Reports poll shows Mr. Obama is surging in Pennsylvania, though still behind Mrs. Clinton. She leads by just 5 percentage points -- 47 percent to 42 percent -- after leading by 10 points a week ago and by 15 points in early March. Mrs. Clinton leads among those concerned most about the economy and Mr. Obama among those most worried about the Iraq war.

A Survey USA poll done for a Philadelphia television station also showed Mrs. Clinton slipping, with her lead shaved to 12 points, down from a 19 points three weeks ago.

Mrs. Clinton told union officials during her 37-minute speech that, if elected, she would invite them to the table when addressing the nation's economic problems.

"Unions built the table, and there are going to be enough seats around it so everyone has a place," she said.

Part of the participation would be by using union labor to help with "rebuilding, repairing and revitalizing" the nation's highway and transit infrastructure, including "immediate safety risks," such as a I-95 bridge in Philadelphia, she said.

She promised to pay for the work with a $10 billion emergency repair fund and to establish an "Infrastructure Bank" backed with what she compared to war bonds.

The work would be environmentally-friendly where possible, she said, while taking a shot at Mr. Obama's Senate votes on energy legislation. "Once again, when it was time to turn talk into action, his action was just words," she said.

Mr. Obama is scheduled to speak to the convention tomorrow.