Obama has already been defeated on health care.
The problem is that the liberal Praetorian Guard have captured the Emperor and won't let him surrender. For example, Paul Krugman wrote:
It’s hard to avoid the sense that Mr. Obama has wasted months trying to appease people who can’t be appeased, and who take every concession as a sign that he can be rolled.
Indeed, no sooner were there reports that the administration might accept co-ops as an alternative to the public option than G.O.P. leaders announced that co-ops, too, were unacceptable.
So progressives are now in revolt. Mr. Obama took their trust for granted, and in the process lost it. And now he needs to win it back.