MIDDLETOWN, N.J. - For Senator Barack Obama, the television image of his day on Friday took place on the floor of a glass manufacturing plant in the small Pennsylvania town of Duryea. But by nightfall, he was a world away from that scene, as he arrived here for a pair of high-dollar fund-raisers.

The singer Jon Bon Jovi and a nearby neighbor hosted back-to-back events for Mr. Obama. While his message was largely the same - criticizing Republicans for their convention message - he steeled his supporters for a tough battle ahead in the final 60 days of the campaign.

"I hope you guys are up for a fight. I hope you guys are game because I haven't been putting up with 19 months of airplanes and hotel food and missing my babies and my wife - I didn't put up for that stuff just to come in second," he said. "I don't believe in coming in second. The American people can't afford for us to come in second."

As he stood beneath a tent on the expansive Bon Jovi compound, which resembled an Italian villa, Mr. Obama criticized the message of the Republican convention. He even suggested that his rival was running a negative race - perhaps more so than Mr. McCain would like, but offered no evidence to bolster his point.

"I think some of you saw this week the strategy of the other side," Mr. Obama said. "A strategy that I'd be willing to venture that if you asked John McCain, 'Is this the kind of campaign he intended, he might have said no."

Neither the images nor the words from his evening will ever appear on television.

The campaign of Mr. Obama, like many other candidates including Mr. McCain, almost never allows cameras inside fund-raising events. The images advisers prefer to see on the evening news and cable television are of Mr. Obama wearing shirtsleeves and safety goggles, not shaking hands with Mr. Bon Jovi and a few hundred other top contributors at riverside mansions.

To a crowd of already committed supporters, who paid either $2,300 or $30,800 to attend, he spent more time talking about his opponents than his own message. He did not mention the names of either vice presidential running-mate - even his own - as he warned his contributors for a blistering two months to come.

"For the next 60 days," Mr. Obama said, "their assignment is going to be to see if they can snuff out that spirit in this campaign and to knock me down more than one peg."

The evening was awash in politics, with no singing from the suit-and-tie wearing Mr. Bon Jovi. He did, however, deliver a few remarks as he introduced Mr. Obama.

"You don't have to be 72 to have experience," he said, referring to the age of Mr. McCain. "It's the end of an era and the beginning of a new one. This 21st century man has an aura of hope wrapped around him."