The dust-up is the latest in a career of risky moves that have paid off handsomely for Madonna, whose tours and albums have long mixed music with politics, sex and religion. While other stars rose to fame in the 1980s then faded away, "Material Girl" Madonna has become a global star and even courted controversy to stay relevant to younger audiences.
"Madonna seems to be a brilliant business woman in the culture scene," said Robert Thompson, a professor of media and pop culture at Syracuse University.
"She's controlled her controversy, so every time she's been in controversy it does her good not bad," he told Reuters.
As her world tour opened in Cardiff, Wales, over the weekend, Madonna showed a video montage juxtaposing images of Hitler with McCain, the Republican senator from Arizona running for president against Democratic Sen. Barack Obama. The Democrats on Monday launched their nominating convention.
McCain's campaign blasted Madonna with a spokesman telling media organisations that the video was "outrageous, unacceptable and crudely divisive."
Abraham Foxman, national director for Jewish group The Anti-Defamation League also issued a statement calling it "outrageous to invoke Nazi imagery in the context of John McCain's candidacy.”
Madonna had previously drawn the ire of the Vatican. Her 1989 song "Like A Prayer," with links between religion and eroticism, caused Pepsi-Cola to cancel a sponsorship deal.
While Thompson noted that Madonna has successfully boosted her career in the past with controversy, he added that celebrities should speak their minds if they want.
But David Horowitz, a conservative writer and activist, took a more dim view of Madonna's latest controversy.
"We're in a sad situation if we're turning to entertainers for political wisdom," he told Reuters.
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