If you folks on the right had asked one of us *liberals* back in '08, we'd have told you Obama wasn't one of us. He's essentially what would have been a centrist Republican thirty years ago. These were people, like Bob Dole, that we liberals didn't agree with, but could respect and work with. In fact, "Obamacare" pretty much follows the private sector oriented reform plans of Bob Dole. If Obama were a liberal he'd have gone with single payer, and negotiated tough price concessions with pharmaceutical manufacturers (which is the source of America's runaway heath care spending). You'd have seen banks regulated or broken apart, and criminal investigations in response to the financial crisis of '08, not an attempt to put the system back together again the way it was before the crash.
In fact Obama is very much the kind of president Dole would have been: an economic pragmatist, a diplomatic multilateralist, and an aggressive user of military force where he perceives an imminent threat to national security.
If you want to stop state intrusion into private affairs, you've got to stop being afraid, and convince others around you to stop being afraid. The more fear there is in the political climate, the more impunity the government has in its actions.
Liberals got behind Obama in '08 for the same reason we got behind Obamacare: we backed the best alternative achievable in a climate of fear -- a climate, by the way, that makes the state internal security apparatus feel empowered to do anything it wants in the search for terrorists.