I'd say kickbacks to city hall and cops counts as corrupting democracy. Likewise, maybe they didn't kill as many or threaten our democracy, but I'm sure if they could have made more profit doing so they would not have hesitated. Still, I get your point. Perhaps we could post their pictures in order of who did the worst deeds.
First, I meant our national democracy. The only time I recall them playing a role there, they ended up probably not changing anything, but helping the right guy, Kennedy.
Second, the point was partly tongue in cheek, of course they threatened the honesty of local and state governments - if not to the degree the Koch organizations do nationally.
The Koches are out to do things like destroy unions, harming the middle class; the mob backed unions, as a source of corrupt funds, inadvertantly helping the middle class.
You know, I think I might have just outed the reason why Reagan went after organized crime - as union busting!