I think a lot of people aren't aware of this, but the US has helped (sometimes very directly) to overthrow quite a few democracies. Look at Iran, and their transition to the Shah; or Allende/Pinochet and Milton Friedman's experiments.
I've looked into some detail on the Iran issue and i suggest others do to. To say the US "overthrew" the Iranian gov't does tell the whole story. There was a large, domestic grassroots effort in Iran to overthrow Mossadegh. Did the US and Britian help that effort? Sure, but to say they imposed their will on the country is going a bit far.
