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Ahead of the Democratic National Convention Vice President Biden summed up how the Democrats hope the country views the past four years, telling a Detroit Labor Day crowd that "Osama bin Laden is dead and General Motors is alive."

But Vice Presidential candidate Paul Ryan shot back today telling me that General Motors isn't alive in his hometown of Janesville, Wisc.

"The president came to Janesville…before the plant shut down and said he would lead an effort to retool the plant. After the plant was shut down he said he would lead an effort to retool the plant to get people back to work. They're still not back to work," he said. "I really ask the 23 million people George who are struggling to find work in America today if we're better off than we were four years ago?"

The congressman says the Romney-Ryan ticket offers "big solutions in a big year" to create jobs, lower our debt, lower our taxes and create economic growth.

But the Democrats are taking aim at those ideas, accusing the Romney tax plan of raising taxes on the middle class by $2,000.

"Not true. What we're saying is we're going to reduce people's tax rates by 20% and we'll do it by closing loopholes. Here's the point, George. We believe that there's a bipartisan consensus to be had through this kind of tax reform," Ryan said. "Democrats like the Simpson-Bowles Democrats agree with us that we should be lowering tax rates and broadening the base by plugging loopholes so that people get to keep more of their own money, so that families with small businesses can have a fair, simple…tax system. We think that's one of the keys to economic growth."

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The non-partisan Tax Policy Center analyzed Ryan's budget plan and said that he cannot lower taxes and raise enough money by just going after loop holes.

Ryan disagreed:

"What other groups have shown is you can do this. Look, George, economic growth is the key to this and one of the keys to economic growth is tax reform. And when we keep taxing our families and successful small businesses at much higher tax rates than our foreign competitors tax theirs, we make our businesses less competitive," he said. "Don't forget the fact, George, that eight out of 10 businesses file their taxes as individuals. President Obama wants their tax rate to go above 40%. Other countries are lowering their tax rates on their businesses. President Obama is promising a higher tax rate. More to the point, he uses this money for more spending. We don't think we should be taxing small businesses and families more to spend the money in Washington."

On the campaign trail Ryan has accused Democrats of "raiding" Medicare by taking $716 billion to pay for the president's health care plan.

And although Ryan wrote and pushed a budget through the House with those same savings, he told me he his budget is based on current law.

"Don't forget the fact that we've already vote and we've already proposed to repeal Obamacare, every part of Obamacare, including this raid of $716 billion from Medicare to pay for Obamacare. They can't have it both ways, George. You can't spend the same dollar twice. You can't say that Obamacare is a cost-saver and that we're extending the life of Medicare. One or the other. The point is, and this has been pretty well verified and established, taking $716 billion from Medicare to finance Obamacare, that really is a raid of Medicare for Obamacare. We think that's wrong. Our plan to save Medicare does not affect or change the benefits for any that is in or near retirement," he told me.

- George Stephanopoulos