I can only speak for the Blues group that I worked for. They are the largest Blues group in the country ... 5 states. They were totally against it and the higher ups made many trips to DC and fought against it. They also encouraged the PAC to contact their congress critters and tell them to vote “no.”
And given this Blues influence on the other leading insurers, I’m sure they got others to work with them. The Obama administration probably ended up paying them off somehow.
http://talkingpointsmemo.com/dc/walgreens-blue-cross-team-up-to-promote-obamacare
Still, its not just that Blues will offer coverage in places other carriers may avoid. In states where Republican governors oppose the health law, Blues may be the single biggest factor in educating consumers and recruiting them into Obamacare.