In the closing sprint to the election, Sens. Barack Obama and John McCain both will appear in Pennsylvania today -- a rare blue state convergence in a campaign where the battlegrounds have been almost exclusively red states won by President Bush four years ago.

The Democratic nominee is scheduled to speak at a late afternoon rally in Mellon Arena. At roughly the same time, Mr. McCain will be appearing in Schuylkill County, continuing the GOP ticket's persistent long-shot quest to capture the state's 21 electoral votes. Mr. Obama will follow his Pittsburgh stop with another rally tomorrow in Chester County, in what could be his last stop in the state before Election Day.

Continuing his long-standing focus on a state in which he has consistently trailed in the polls, Mr. McCain will rendezvous with his running mate, Gov. Sarah Palin, for rallies tomorrow in Hershey and Bucks County. The Alaska governor will then head out on her own to events in the college towns of Shippensburg and State College.

The Pennsylvania campaigning occurs as the Republican has just over a week to reverse national and key state dynamics that have favored his opponent as concerns about the economy have crowded out other issues.

Appearing on "Meet the Press" yesterday, the Arizona senator professed to be undaunted.

"I see the intensity out there, and I see the passion," he told Tom Brokaw while insisting that public surveys "have shown me much further behind than we actually are."

"We're doing fine," he added. "We are very competitive in many of the battleground states."

His campaign insists that Pennsylvania is one of them, despite a variety of polls showing a double-digit deficit that has failed to yield to an extensive commitment of personal campaign time from the Republican nominee.

"I guarantee you that two weeks from now, you will see this has been a very close race, and I believe that I'm going to win it," Mr. McCain said in the NBC interview.

Mr. Obama was in Colorado yesterday, a state that Mr. Bush won twice but one whose electoral votes appear to be within the Democrat's grasp.

In Pennsylvania, yesterday's Muhlenberg College tracking poll showed Mr. Obama leading by 53 percent to 40 percent, a margin that hasn't moved significantly for weeks. The lack of traction for the GOP ticket raises the question of whether they wouldn't be better off spending the dwindling amount of campaign time they have on states in which they are more competitive.

"They don't have much choice," said Terry Madonna, the director of the Franklin and Marshall College poll.

The political scientist noted that the Democrat is now leading in nine states carried by a president who won the Electoral College by 16 votes.

"[McCain] is not winning a single Kerry state. He is going to lose at least some of those nine Bush states, so just start doing the math; he's got to make it up somewhere.

"They've made a decision that this is their best chance of all of the Kerry states. They might have a shot in New Hampshire, but they can spend all the time they want in New Hampshire and it still only has 4 [electoral] votes. So they're stuck," he said. "[Pennsylvania] may not be the best possibility, but it's the only possibility he has."

Peter Feldman, a spokesman for the Republican campaign, offered a more positive assessment of its prospects here.

"We have it close; we're going to carry Pennsylvania," he said. "That's why you're seeing all this."

Mr. Obama will travel to Pittsburgh after an earlier appearance in Canton, Ohio. At both stops he is expected to deliver what his campaign bills as a closing argument to his months of campaigning for the White House. According to a statement issued by the campaign, Mr. Obama will once again portray Mr. McCain as an heir to the polices of President Bush while renewing his own promises on issues including the economy and health care.

The doors to Mr. Obama's Mellon Arena event, which is open to the public, will open at 3 p.m., although the candidate, typically, would not be expected to appear until some time later.