The NYT had a story on these lines today. Their graphic – not as striking as the one above – is here. Along the same lines, the WaPo reported yesterday that from "1984 and 2009, the median net worth of a member of the House has risen 2½ times … rising from $280,000 to $725,000 in inflation-adjusted dollars." Kevin Drum's analysis:
It just costs too much to run for Congress today for anyone who's not fairly well off to do it. And that's no coincidence. As income inequality goes up, campaign funding from rich donors also goes up — partly because the rich have more money and partly because they're more motivated to use that money to influence the political process in order to protect their wealth. This creates an arms race that effectively precludes anyone who doesn't have either money of their own or access to wealthy donors from running.