By Patrick Healy and Katharine Q. Seelye

updated 4:09 a.m. ET Aug. 22, 2008

Barack Obama and John McCain ripped into each other on Thursday over how many houses, fireplaces and even wine cellars they own, using allusions to net worth to deride each other while portraying themselves as able helmsmen for a faltering economy.

With both candidates convinced that financially pinched voters might hold the electoral key in November — especially in swing states like Ohio and Pennsylvania — Senators Obama and McCain are taking new, vivid steps to empathize with struggling middle-class and working-class Americans, a tricky task given their own personal wealth.

In a new television advertisement and at an event in Virginia on Thursday, Mr. Obama seized on new comments by Mr. McCain, made a day earlier, expressing uncertainty about the number of homes he owned. (Eight, with his wife, Obama aides said; four, McCain aides said.) Obama advisers cast the McCain remark as politically explosive, contrasting it with the mortgage foreclosure crisis that has upended the American dream of owning even one home.

The McCain camp swiftly countered with its own advertisement and condemnations, noting that Mr. Obama owns a “mansion” — a disputable characterization — with four fireplaces in Chicago, and reviving questions about his land deal with Antoin Rezko, a businessman who was convicted in June on fraud and corruption charges.

The exchange highlighted how, as economic issues increasingly dominate the campaign, the two presumptive presidential nominees are still searching for ways to connect with voters on the economy. Mr. Obama sometimes seems professorial in response to personal problems, while Mr. McCain seemed more than half-serious on Saturday when he defined “rich” as having $5 million or more.

“It’s now clear that the economy will be the tipping point in this election,” said Jack F. Kemp, the Republican vice-presidential nominee in 1996 and a former housing secretary, “and the candidate who has the best answer to getting America growing again without inflation is going to tap the winning segment of this electorate.

“I like John’s ideas, but he has more to do in terms of making his case and connecting with voters on the economy.”

For all the candidates’ detailed position papers, many undecided taxpayers and homeowners appear to be looking at the candidates themselves, as well as their speeches, body language and stagecraft, in hopes of making a visceral identification.

Part of the challenge for both men is that they have campaigned largely on character traits: Mr. McCain, Republican of Arizona, as a war hero who stuck with the troop surge in Iraq in spite of criticism, and Mr. Obama, Democrat of Illinois, as a change agent who would unite voters with a hopeful message.

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“Obama has the better set of policies,” said Robert E. Rubin, a former secretary of the Treasury under President Bill Clinton. “But has he effectively conveyed those policies in a way that votes will understand? That’s the challenge for his campaign.”

And one way for each to connect with voters is to suggest his opponent’s own lack of understanding of the economic struggles facing Americans, which was underscored by the exchanges on Thursday.

Mr. Obama became a millionaire by writing books, and he lost primaries this spring in Indiana, Ohio and Pennsylvania to a rival who appealed to voters with a can-do political platform on pocketbook issues, Senator Hillary Rodham Clinton of New York. Mr. McCain, meanwhile, overcame a primary challenge from former Gov. Mitt Romney of Massachusetts, a wealthy executive who also focused on the economy.

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