It is one of the great moans of vast numbers of American voters: Washington politicians are just not like them. They are different. They are a breed apart, unable to understand what real life is like for tens of millions of ordinary folks.

Well, now an excellent report has emerged to point out one important way America's nationally elected politicians are, indeed, very different from the recession-plagued and foreclosure-fearing masses. Most of them are rich. Often, very, very rich.

According to the survey, by the Centre for Responsive Politics, almost half of America's senators and members of the House of Representatives are millionaires. A full 261 one of them, in fact. Meanwhile, a mere 1% of the rest of Americans can claim such exalted status.

That is a staggering and crucial difference between America's elected leaders and the people who put them there – and in some cases, "millionaire' does even get near describing it. A startling 55 of the congressional plutocrats are worth more than $10m (and the database the CRP used does not even include the value of their homes). The richest is Californian congressman Darrell Issa, whose wealth lurks somewhere around $250m.

But this is far from being a partisan problem. The second wealthiest is Californian Democrat Jane Harman, who is worth just $6m less than Issa.

No wonder America's body politic can seem to be a little slow when it comes to reflecting the day-to-day concerns of many Americans. No wonder it is currently obsessed with working out a way to keep President George W Bush's tax cuts for the rich in place. No wonder it is seemingly willing to let slide vital unemployment benefits for millions of Americans who are now entering the ranks of the long-term jobless. No wonder it is keen to bail out the financial industry and keep bankers cashing their bonus cheques, even as it shrugs its shoulders at creating jobs for those outside the vaulted halls of the finance industry.

This is appalling. Any group of politicians in a democratic country is supposed to represent that nation in all its complexity. They are meant to be the people in microcosm. That is why we celebrate when female politicians break through – whether Sarah Palin or Hillary Clinton. That is why the election of a black president was so exciting. That is why all America should be pleased at the growing representation of Hispanic politicians. Or Asian ones. No matter what party those politicians come from, their different gender and ethnic backgrounds bring a diversity of experience into a body too often dominated by old, white men.

But why should an exception be made for the rich? Having only the wealthy elected to Congress hardly helps diversity of opinion or interest – except to bias it towards the wealthy. What would be really radical about an American election would not be electing more women, or more blacks, or more Hispanics, or more Muslims, but some poor people. Not those who were born poor but made good (like Senator Harry Reid, for example), but those who know what struggling in today's economy really feels like.

After all, with 50 million Americans facing food insecurity and a poverty rate near 15%, it is not like they are in short supply.