Middle class -- whatever it is -- targeted by candidates Mitt Romney's campaign has released a new ad suggesting President Obama would raise taxes on the middle class. Vice President Joe Biden went on the defensive saying the president would raise taxes, but not on the middle class. The Washington Post's Eugene Robinson joins a Friday wrap-up analyzing the first presidential debate of 2012. What is the middle class, anyway? There's no official definition, but Americans and their leaders seem to know it when they see it. And after five tough years of a recession and slow economy, there's plenty of evidence that fewer people see a middle-class life when they look in the mirror. "You can't define middle class, but you can ask people, "Do you still feel middle class?" And more and more people don't," said Tim Smeeding, director of the Institute for Research on Poverty at the University of Wisconsin. Still, as election season heats up, that's not stopping many politicians from promising to help the middle class, whoever they may be. "The whole attraction of middle class ... is it doesn't mean anything," said Dennis Gilbert, a sociology professor at Hamilton College who studies class issues. Middle class means anybody who might vote for you. The focus on the middle class starts at the top of the ticket, where President Barack Obama and Republican challenger Mitt Romney have both repeatedly invoked the middle class in their quest to win the presidency next month. Obama told voters during last week's debate that he cut taxes for middle-class families "because I believe that we do best when the middle class is doing well." Then he questioned whether Romney had the same dedication to the middle class. And at some point, I think the American people have to ask themselves, is the reason that Governor Romney is keeping all these plans to replace secret because they're too good? Is it -- is it because that somehow middle-class families are going to benefit too much from them? Obama said, according to a transcript provided by the Commission on Presidential Debates. Romney argued that Obama's policies have hurt the middle class and would continue to do so. "There's no question in my mind that if the president were to be re-elected you'll continue to see a middle-class squeeze with incomes going down and prices going up," he said during the debate. I'll get incomes up again. The traditional political focus on the middle class comes as fewer people feel like they're still part of it. A Pew Research Center report this year found that 49 percent of people define themselves as middle class, down from 53 percent from four years ago. "Statistically, that's a significant shift, but beyond statistics it feels right," said Rich Morin, a senior editor with Pew Research Center. It's been a tough four years. In fact, Morin said, Americans" sense of how the middle part of the economic spectrum is doing is surprisingly accurate. The polling data on whether Americans feel like they are still part of the middle class matches well with the researchers" economic data on median income in the United States, which has fallen in recent years after adjusting for inflation. Still, experts say the term middle class has a cultural connotation that goes beyond the number on your paycheck or tax stub. Kevin Leicht, director of the Iowa Social Science Research Center at the University of Iowa, said many Americans think of a middle-class life as being one in which you have a stable job, own your own home and occasionally buy something substantial like a new car. You also either went to college or have the aspiration of sending your children to college. Beyond that, he said, the term middle class invokes the type of person who gets married and has kids, pays their bills on time, doesn't get in trouble with the law and maybe goes to church. "In the United States, it's probably more of a cultural category than an economic one," he said. He thinks Americans" affinity for the middle class also comes partly from a natural suspicion for both the richest and the poorest Americans. Audacious wealth has traditionally been frowned upon in this country, he said, while there's also often a fear-based bias against people who are poor. "Because a lot of us are two missed paychecks away from being in exactly the same position, we have to act like there's something systematically wrong with people who are in that position," Leicht said. The sense of a shrinking middle class also comes amid evidence that the rich are getting richer and the poor are getting poorer, discouraging many Americans. They are aware that economic inequality is growing. And a majority - a substantial majority - say it's a bad thing," Morin said. Everyone aspires to be upper class, but people are aware that as more Americans move up into the upper class, more Americans are moving down, and that's not a good thing. The big question now is whether Americans" discouraged attitudes about the middle class will change if the economic recovery starts to pick up. In general, experts say that history would show that Americans will grow more optimistic about the middle class, and the American dream, as economic conditions improve. But, they note, this recession and weak recovery has been different from any other we've experienced in recent decades, and the future remains uncertain. "I'm sure a strong recovery would help, but that's a ways off," Smeeding said. Our standard of living is lower now than it was in 2006. Readers, how do you define a middle class life and do you think you are living it? Send me an e-mail, including contact information, and and we'll use some of your responses in an upcoming story. Rags to riches? That's Hollywood fiction, study finds Many in middle class say they are doing worse financially Economy's long slump pushing many down the ladder