What drove the costs of the "Cadillac plans" up was that the members worked in injury-prone industries, i.e. fishing, construction &c. The benefits weren't particularly rich. Small wonder that the unions in those industries would come out against provisions that would penalize their members for working in their line of work.
There's plenty of things wrong with US unions, but opposition of fishermen to Obamacare isn't amongst them.
There's plenty of things wrong with US unions, but opposition of fishermen to Obamacare isn't amongst them.