John McCainJohn McCainBush biographer: Trump has moved the goalpost for civilized society White House to pressure McConnell on ObamaCare McCain: Trump needs to state difference between bigots and those fighting hate MORE praises American workers and denounces Wall Street in his latest TV ad, blaming "greed" among financial firms and stock traders for current U.S. economic conditions.

Since the collapse of investment bank Lehman Brothers and the sale of financial firm Merrill Lynch Monday, McCain has stumped for reforming Wall Street, alleging greed, waste, and corruption in the nation's financial systems.

That argument has become central to McCain's economic platform, and today's ad is his second this week to advocate for Wall Street reforms.