SCRANTON -- Three senators with roots in this hard-coal country joined former President Bill Clinton yesterday, invoking their shared heritage in pursuit of votes for Sen. Barack Obama.

"It is great being back here in Scranton," Sen. Hillary Rodham Clinton said as she followed husband to the microphone. "We wanted to be back here together [to make] a simple message abundantly clear. We must elect Barack Obama and Joe Biden.''

This was Clinton country during the Pennsylvania primary, and while Mr. Obama's poll numbers have climbed statewide, the region remains a challenge for the Democratic ticket.

A Franklin & Marshall College poll released earlier this month, showed Mr. Obama with an expanding lead statewide, but Sen. John McCain retained a narrow advantage here in Pennsylvania's northeast corner.

Sen. Bob Casey, the native son who helped warm up the crowd for the Clintons and Sen. Joseph R. Biden Jr., the Democrats' vice presidential candidate, told reporters afterward that Democrats still had work to do to win Democratic support in Democratic areas like Scranton.

If the Clintons retain hard feelings from their long nomination battle with Mr. Obama, they didn't display them yesterday, although the former president's message often focused as much on his wife as on the nominee.

"She has done 50 events for Sen. Obama," he reminded the crowd. "I expect to spend the rest of my natural life trying to show people how grateful I am [to those] who supported Hillary.

"She has not only done more to support [Mr. Obama] than any runner-up in a Democratic primary process in my lifetime; she has done more than all the other runners-up combined -- and that says a lot about why she ran for president and what she believes in."

Still, as in his convention speech in Denver, Mr. Clinton was unambiguous in calling for her onetime rival's election, arguing that Mr. Obama has "the best ideas," and "the best supporting cast.''

"That's why I'm here. That's why Hillary's here," he said.

As she introduced Mr. Biden, Mrs. Clinton reminded the crowd of the Scranton roots she had mentioned time after time on her way to a nine-point victory in the state's April primary.

"It starts right here in Scranton where my father was raised and where he is buried,'' she said.

She described Mr. Obama as a president who would deal capably with the battered economy and make strides toward her oft-promised goal of more affordable health care.

At one point, she referred to the Democratic nominee with a line she had used countless times through their hard-fought primaries to describe herself: "You deserve a president who will get up every day thinking of you."

That was one of several times she molded passages from her former stump speeches to fit the new political circumstances.

Echoing another of her signature lines from the primaries, she said: "It took a Democratic president to clean up after the last President Bush. It's going to take a Democratic president to clean up after this President [Bush]."

Through the winter and spring, however, she had predicted that "a Clinton," rather than, "a Democrat," would do the cleaning.

Their Republican opponents showed they hadn't forgotten the primaries either.

A spokesman for the McCain campaign dispatched an e-mail reminding reporters of a litany of criticisms of Mr. Obama that Mrs. Clinton and Mr. Biden had voiced when they were vying with him for the nomination.

"As voters in northeast Pennsylvania continue to raise serious questions about Barack Obama's judgment and character, it is befitting that they will now hear from the three leading voices who sounded the alarm on the risk of an Obama presidency," Paul Lindsay said in the statement. "Whether it was calling a vote for him a roll of the dice or attacking his relationship with unrepentant terrorist William Ayers, Joe Biden and the Clintons were right -- Obama's poor judgment proves he is not ready to lead."

Mr. Biden has a different target now, and he enthusiastically took aim at it as he decried Mr. McCain as a disciple of President Bush and an advocate of polices that he blamed for the crisis in the world economy.

He repeated the frequent Democratic criticism of Mr. McCain's mid-September characterization of the economy as fundamentally sound.

Noting that the GOP nominee had quickly qualified that observation, Mr. Biden said, "John's epiphany wasn't that he saw the light. John's epiphany was that he saw the presidency receding from his grasp."

To face the demands of the economic crisis he said, voters have a choice between "the steady hand of Barack Obama or the unsteady hand of John McCain."

At times, he sounded almost as though he were channeling the actor who portrayed him in a "Saturday Night Live" send-up of his face-off with Gov. Sarah Palin, the Republican vice presidential nominee, as he alternated praise for Mr. McCain's character and military service with scorn for the Republican's policies and voting record.

Mrs. Clinton was scheduled to make another appearance for the Obama campaign today outside Philadelphia.

"I haven't spent 35 years in the trenches fighting for universal health care, for children, for families, for women, for middle-class people to see another Republican in the White House squander the promise of our nation,'' she said.

Alluding to the fact that the Democratic ticket remains a tough sell to at least some local Democrats, she added, "I know you have friends and neighbors who aren't decided yet. ... So I am deputizing every one of you to go out and make the case because Barack and Joe are not asking you to marry them. They are asking you to vote for them -- and vote for yourselves."