A round of applause for Kevin (Calpundit) Drum.
Here he's reproduced a great, easy-to-read table (from The New York Times) that shows that, when all forms of state and local taxes are taken into account, our tax system is virtually flat now -- there's almost no progressivity. Total tax burden for the richest fifth of the country? 19%. For the poorest fifth? 18%.
(Federal income taxes are still somewhat progressive, but there's regressivity in other taxes -- e.g., sales taxes and gasoline taxes, which consume a bigger percentage of poor and working-class people's income than they do of what the rich make.)
But the link is more useful than that. At the link are links to erarlier posts in his blog, which, in turn, contain more information about tax progressivity (or the lack thereof). If you care about this, there's a lot to chew on. At the very least, go to the link, copy and paste the Times chart, and e-mail it to anyone you know who thinks we soak the rich in this country.