Obamacare will probably be a 50-50 type debate by October, barring some unforseen issue. I think the more important thing is the continued realization that no, Obamacare isn't going to destroy healthcare as we know it, kill old people, endanger the disabled, etc. There will be a sizable level of pushback for years, largely from conservatives, but as more regular people begin to not care about the law, it'll become less of a major issue.
A great example is that recent Gallup poll that shows about 56% of republicans believe Obamacare is going to harm them, which is down from like 90% just a few months ago.