The Obama and Romney campaigns released dueling web videos Monday focusing on Mitt Romney's record at private equity firm Bain Capital -- in the latest volley of an intense debate, with the election still six months away.

The Obama campaign has stood by its decision to hammer the presumptive Republican nominee over his tenure at Bain, despite that line of attack backfiring for Romney's former GOP primary opponents. Still, a few prominent Democrats -- most recently Newark Mayor Cory Booker -- have started to question the president's campaign strategy. 

The Romney campaign, in response to a fresh Obama video Monday morning that tied Romney and Bain to an Indiana plant closing two decades ago, released a web video of its own Monday afternoon highlighting that Democratic dissension. 

The video, titled "Big Bain Backfire," featured Booker's comments over the weekend on NBC's "Meet the Press." Booker, who has since walked back his remarks, said Sunday that "I'm not about to sit here and indict private equity." 

The Romney video also featured comments from former Democratic Rep. Harold Ford Jr. and ex-Obama economic adviser Steven Rattner defending private equity and Bain. 

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"Have you had enough of President Obama's attacks on free enterprise?" the video asks. 

The Obama campaign, though, is expanding an ad buy from last week spotlighting a steel company that went bankrupt after Bain's involvement. And on Monday, the campaign released another "Romney Economics" web video spotlighting Bain-owned paper company Ampad. 

According to the campaign, the company bought and closed a Marion, Ind., plant in 1994, costing 250 jobs. 

"Bain, Mitt Romney -- they did not care about us as workers. They were looking at the mighty dollar," one former worker in the ad says. 

The ad says Romney and his partners multiplied their investment in the office products plant by 20 times while the company went on to lose some 1,500 jobs and went bankrupt by 2000. Former Ampad worker Randy Johnson called Romney's performance "just the opposite of Robin Hood." 

Meanwhile, Booker continued to take heat for his outspoken comments on Sunday. Despite releasing a three-minute video since those comments walking back his remarks, Obama campaign strategist David Axelrod said Sunday Booker was "wrong" to say what he did on Sunday.   

"In this particular instance, he was just wrong," Axelrod said on MSNBC Monday. "There were specific instances here that speak to an economic theory that isn't the right theory for the country." 

"I love Cory Booker. He's a great mayor," Axelrod added. "If my house was on fire, I'd hope he was my next door neighbor." 

Axelrod was referring to Booker's local heroics, which include saving his neighbor from a burning building and helping dig out stranded residents during the 2010 blizzard. 

NewsCore and The Associated Press contributed to this report.