WASHINGTON - Sen. John McCain's inability to recall the number of homes he owns during an interview Thursday jeopardized his campaign's carefully constructed strategy to frame Democratic rival Barack Obama as an out-of-touch elitist.

It also inspired a round of attacks that once again ratcheted up the negative tone of the race for the White House.

In an interview with Politico.com, the presumptive Republican nominee was asked how many houses he and his wife, Cindy, heir to a beer distributorship, owned.

"I think -- I'll have my staff get to you," McCain replied. "It's condominiums where -- I'll have them get to you."

Obama's campaign and the Democratic National Committee pounced with remarkable speed. By mid-morning, reporters had received a video log featuring Cindy McCain's childhood estate in Phoenix, an Architectural Digest spread on another property the McCains had owned previously, and tax records and photos detailing seven houses and condominiums. By 11 a.m., the Obama campaign had produced a TV advertisement titled "Seven" and was answering the question McCain could not.

"It's seven, seven houses, and here's one house Americans can't afford John McCain to move into," the ad concludes over an image of the White House. (If a condo that Cindy McCain purchased for their children this year is included, the number rises to eight.)

That provoked a furious response by McCain campaign and Republican National Committee aides, who charged hypocrisy and argued that the senator from Illinois had received help purchasing his South Side Chicago mansion from businessman Tony Rezko, a convicted felon.

"Does a guy who made more than $4 million last year, just got back from vacation on a private beach in Hawaii and bought his own million-dollar mansion with the help of a convicted felon really want to get into a debate about houses?" asked McCain spokesman Brian Rogers.

The senator from Arizona also quickly assembled a response ad that raises Obama's relationship with Rezko. A narrator intones, "Barack Obama knows a lot about housing problems."

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