It's just a fact that a majority of the people elected to Congress are millionaires or billionaires. One reason for that is how expensive it is to run in even a House race (and more expensive to run in a Senate race). For example, in the recent House special election to fill Georgia's 6th District seat, about $50 million was spent (about $23 million for the Democratic candidate and $27 million for the Republican candidate).
That has the public thinking it's not affordable for an ordinary citizen to run for Congress. A candidate must either be rich, or they must sell out to the rich for donations -- and neither option benefits the ordinary citizen (who wants a candidate that will work for the working and middle classes).
That's the opinion of an overwhelming majority of the public in a new Rasmussen Poll -- done on June 20th and 21st of a random national sample of 1,000 likely voters, with a 3 point margin of error.