In CA one of these strong relationships is between the prison guards' union and Sacramento. Little wonder that this union contributes a huge percentage of Sacramento's campaign finance dollars, and that in return CA prisons have the second-highest per-capita cost in the US. We are literally paying tax dollars for prisons and guards, who in turn give those same dollars to state politicians for re-election, who in turn continue to enforce legislation which keeps prison costs high.
But the poster child for union/politician aggrandizement is Detroit. There are several factors that led to this city's demise, but most apparent is the 40-year-long collusion of union members and politicians. Yes of course the auto companies had a part, but they themselves would not be able to do much of anything without support from unions and Michigan politicians alike.
We've all seen pictures of the razed areas of Detroit that make the city look like a war zone. Try this - I tried it today and I was flabbergasted. Go to Google maps, look for the area surrounding downtown Detroit - and do a street view. Look north, or east, or west, it doesn't matter, it's the same. I am amazed at just how barren the cityscape is.
They enjoyed the ride for 40 years, but they're paying for it now.