John McCainJohn Sidney McCain3 real problems Republicans need to address to win in 2020 Fighter pilot vs. astronaut match-up in Arizona could determine control of Senate The Hill's Morning Report — Recession fears climb and markets dive — now what? 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.