HERSHEY, Pa. (AP) — Republican John McCain and running mate Sarah Palin told a Pennsylvania audience Tuesday that ‘‘it’s wonderful to fool the pundits’’ and vowed to pull out an upset win over Democratic rival Barack Obama.

‘‘I’m not afraid of the fight, I’m ready for it,’’ said McCain, continuing his sharp assault on Obama at a noisy rally opening his campaign day.

Palin defended the campaign’s harsh attacks on Obama.

‘‘Our opponent is not being candid with you about his tax plans,’’ said Palin. ‘‘It is not mean-spirited, and it is not negative campaigning to call out someone on their record.’’

Obama backers waving signs briefly interrupted the rally, a move Palin dismissed.

‘‘When we get a protest like that I’m always tempted to tell security, ‘let them stay, maybe they’ll learn a thing or two,’’’ Palin said.

The campaign day was complicated by wintry weather that forced the cancellation of an outdoor event in Quakertown. McCain headed to North Carolina and Florida before the day was over. Palin was heading on her own to other events in Pennsylvania after the rally in Hershey.

Sagging in polls nationally and in battleground states, McCain worked to light a fire under his supporters.

‘‘Nothing is inevitable, we never give up,’’ he said. ‘‘Let’s go win this election and get this country moving again.’’

Most polls have shown Obama with a lead in the race for Pennsylvania’s 21 electoral votes, but McCain dismissed those surveys and urged a sprint to the finish.

‘‘It’s wonderful to be back in Pennsylvania,’’ he said. ‘‘It’s wonderful to fool the pundits because we’re going to win the state of Pennsylvania.’’

Pennsylvania is the only state won by Democrat John Kerry in 2004 where McCain is still mounting a full-scale campaign. Both the Republican and Democratic tickets are focusing heavily in the closing days on a few key battleground states, including Pennsylvania, Ohio, Florida and Virginia.

McCain continued to label Obama a traditional liberal Democrat seeking to redistribute the wealth.

‘‘Sen. Obama is running to be redistributor in chief, I’m running to be commander in chief,’’ said McCain. ‘‘Sen. Obama is running to punish the successful, I’m running to make everyone successful.’’

McCain also returned to the theme that he’s the candidate who is ready to take office, seasoned by a military career and his experience as a prisoner of war in Vietnam. He brought up their differences over the Iraq war. McCain opposes and Obama favors a timetable for withdrawal of U.S. combat troops.

‘‘Have you ever heard the word ‘victory’ pass through Obama’s lips?’’ McCain asked backers. ‘‘My friends, we’re winning in Iraq.’’

McCain hammered that message later in Fayetteville, N.C., a battleground with a big military presence, like nearby Fort Bragg.

‘‘We need a president who has actually fought for change and made it happen,’’ said McCain, warning of a dangerous world that he’s best equipped to face. ‘‘The next president won’t have time to get used to the office.’’

McCain argued his military career and prisoner-of-war background have shaped his life

‘‘I’ve been tested, Sen. Obama has not been tested, I won’t be a president who has to be tested,’’ he said. ‘‘I’ve fought for you in places where defeat meant more than returning to the Senate.’’

McCain left few openings untouched, even bashing Obama for airing a 30-minute commercial Wednesday night that will delay the opening of a World Series baseball game if the series goes to six games.

‘‘No one will delay a World Series game with an infomercial when I’m president,’’ said McCain.

While Palin has caused some headaches for the ticket, she’s popular with the Republican base and she added energy to a rally before nearly 10,000 cheering backers.

‘‘You are such a welcoming and patriotic state,’’ Palin said. ‘‘I know we have many patriots in the crowd today.’’

Palin also predicted a tight election: ‘‘It’s going to be a hard-fought contest and it’s going to come down to the wire.’’