Elizabeth Warren, one of the leading
Democratic presidential candidates, has stepped up her assault on billionaires -- a rallying cry popular with her base, but one that could stymie her efforts to garner wider support among US voters.
The one-minute campaign ad shows clips of several leading businessmen criticizing her plans for a wealth tax and predicting economic ruin if she is elected to succeed
Donald Trump, a billionaire himself.
Then the viewer sees Warren at a campaign rally, challenging America's most wealthy to pay up to help reduce income inequality in America.