At a campaign stop in Youngstown, Ohio, today, Vice President Joe Biden lit into Republicans and their presumed  presidential nominee Mitt Romney for what he described as a failure to understand the plight of the middle class.

"I resent when they talk about families like mine that I grew up in. I resent the fact that they think we're talking about  envy: it's job envy, it's wealthy envy; that we don't dream," an impassioned Biden told a crowd of manufacturing workers.

"My mother believed and my father believed that if I wanted to be president of the United States, that I could be, I could be vice president! My mother and father believed that if my brother or sister wanted to be a millionaire, they could be a millionaire! My mother and father dreamed as much as any rich guy dreams!

"They don't get us! They don't get who we are!" he yelled before the crowd, drawing loud applause.

Biden was referring broadly to Republican criticism of the administration's push for higher taxes on wealthier Americans and expanded investment in federal programs aimed at boosting low- to middle-income families.

The vice president argued for a populist vision - "Obama economics" - that "believes everyone deserves a fair shot, a fair shake, and everybody should play by the same rules."

"Then there's the Romney philosophy," he said. "The Romney economics which says as long as the government helps the guys at the top to do well, workers and small business communities, they can fend for themselves but the country will be OK if the big guy is doing well."

For the first time, Biden directly and publicly critiqued Romney's business record at Bain Capital, claiming it illustrates  a worrisome approach to running the U.S. economy.

"By the way, Romney raised this. We didn't raise this. He says it's his business experience. So let's take a hard look at that business experience," Biden said.  "In the 1990s there was a steel mill in Kansas City, Mo. It had been in business since 1888. When Romney and his partners bought that company, eight years later that company was in bankruptcy."

 The case of GST Steel and its 750 laid-off workers is featured in an Obama campaign TV ad running in Ohio and four other states during tonight's network evening newscasts. Romney had left Bain by the time the company went bankrupt, but he retained a financial stake in the firm, which profited from the GST deal.

"Of course, they don't mention a couple of other things, one is we were able to create over 100,00 jobs, and secondly on the president's watch about 100,000 jobs were lost in the auto industry and auto dealers and auto manufacturers," Romney said in a Wednesday radio interview. "So you know, he's hardly one to point a finger, and oh by the way, he has no problem, he has no problem going out and doing fundraisers with Bain Capital and private equity people."

Biden's event was the first stop on a two-day campaign swing through eastern Ohio, a critical general election battleground.