I’m not sure sure they think this will keep them in power forever. They are obsessed with achieving a socialist victory at any cost, no matter what the fallout, even for their party. They believe they will never ever have a chance like today to pass socialized medicine and they are Communists at heart and want to pass it. Also, I can’t imagine socialized medicine being a winner over time. It can eventually be overturned before it ever goes into effect in 2013 with a GOP Congress and a GOP President.
I think that they believe that once it passes it will never be repealed. There is some validity to that belief. If it is modified, that is OK as long as the edifice remains.
But they are not considering what happens if the debt this thing will impose causes instability in the American system (or even outright revolution). That may destroy the edifice as well as them. But then again, as many have observed on this forum, this rush to socialism has a very lemming-like character.