Ezra Klein looked into the possibility of losing the mandate:
Kaiser Health News asked a variety of health-care experts to imagine the worst-case scenario and come up with ideas for a policy that could replace the individual mandate. This doesn't turn out to be all that hard: Late enrollment can be linked to lower subsidies, as it is in Medicare Part D. Or perhaps there's an open enrollment period every year or two, and if you choose not to sign up during that time, you have to wait for the next one. Another idea is that if you won't sign up at the start, your preexisting conditions aren't covered when you do sign up.
Without Republican votes, however, no fix or reform will be possible.
Mark Pauly, who helped develop the mandate as an adviser to George H.W. Bush, doesn't seem that concerned:
"I would prefer to have a mandate to mop up for the well-off uninsured, but I think in the short run we could make a lot of progress with the generous subsidies that are aimed at bringing in the great bulk of the uninsured. Then, we could see where we are and then we could talk about an individual mandate to round up the stragglers. I'd prefer to have one to be safe, but if people are going to get themselves all up in an uproar, then why don't we use the effective tool – subsidies – first and see if we really need it.
The individual mandate has become this enormous distraction which could run the risk of sinking the whole ship. If you had to throw it overboard to save subsidies and exchanges, I would sure throw it overboard myself."
The irony of that outcome is that it pulls the Obama administration back to the plan proposed by the Obama campaign.