On Sunday, Chicago Mayor Rahm Emanuel had this advice for Mitt Romney when it comes to the Obama campaign’s attacks on his Bain Capital record: “Stop whining.”

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Now, Democratic National Committee Chairwoman Debbie Wasserman Schultz is counseling the presumptive GOP nominee’s campaign to “put their big boy and big girl pants on” and defend Romney’s record.

In an interview on MSNBC Monday morning, Wasserman Schultz (D-Fla.) doubled down on the Obama camp’s suggestion that Romney may have violated the law by filing government paperwork stating that he remained with the private-equity firm past 1999, the year he has maintained that he left the firm.

“Well, what (Obama deputy campaign manager) Stephanie (Cutter) said, rightfully so, is that either Mitt Romney was lying on SEC forms and misrepresenting to his investors — which could be a felony — that he was the sole owner, president and CEO of Bain Capital from 1999 until almost the end of 2001, or he wasn’t, and represented that he was,” Wasserman Schultz said. “It can’t be both.”

She added: “You know, this is a campaign for president of the United States. Mitt Romney is running for president of the United States, and he and his campaign leadership need to put their big boy and big girl pants on and defend his record.”

Romney’s camp has responded to the Bain attacks by targeting what it describes as Obama’s “political payoffs” to wealthy donors.

“While middle-class Americans are suffering in the Obama economy, President Obama’s donors and supporters are ‘doing fine,’” Romney spokeswoman Andrea Saul said in a statement Monday morning. “The president has spent billions of taxpayer dollars on political payoffs, but failed to create the millions of jobs he promised. Americans deserve a president who is concerned with creating jobs for the middle class, not rewarding campaign donors. It’s Chicago-style economics, and it’s not working.”

Still, the remarks by Wasserman Schultz are the latest indication that Democrats do not intend to back down from their Bain attacks anytime soon — leaving Romney with a political dilemma.