Click here to watch "Fundamentals."

With Wall Street still reeling from news of Lehman Brothers' failure and Merrill Lynch's sale to Bank of America, Barack Obama is seizing on comments made that same morning by rival John McCain. The only sound in "Fundamentals" (subscription) is ominous music and a familiar line that McCain delivered again Monday in Florida: "Our economy, I think, still -- the fundamentals of our economy are strong."

The 30-second spot -- running in "key states," per the campaign -- flashes various messages underscoring the severity of the financial crisis: "Lehman Brothers collapses," "markets in turmoil," "job losses at 605,000 for the year" and "foreclosures at 9,800 a day." It goes on to air footage of McCain at the Florida rally and asks on screen: "How can John McCain fix our economy if he doesn't understand it's broken?" The ad concludes with the Democrats' signature attack strategy: showing a photo of McCain with the unpopular President Bush.

Obama himself pounced on McCain's comments just hours after McCain made them. At a rally in Colorado, the Illinois senator drew several comparisons between McCain's and Bush's positions on the economy, and sarcastically asked his opponent: "Senator -- what economy are you talking about?"

McCain, meanwhile, is not sitting out Wall Street's emergency; while the fundamentals are strong, he told his Florida audience, they are still "at risk because some on Wall Street have treated Wall Street like a casino." His campaign had a new ad up Monday asserting that the economy was in a "crisis" and touting himself and running mate Sarah Palin as the "only" ones who can fix the economy.