Nate Silver’s advice for gauging the political impact of overturning Obamacare:
[T]o the extent there are political implications from the court’s ruling, they are likely to stem from the headlines and not the fine print. If the court strikes the individual mandate while leaving the rest of the bill intact, for instance, Republicans will still have a strong talking point – the Supreme Court has ruled Mr. Obama’s most ambitious policy unconstitutional – even though this might represent a decent policy outcome for Mr. Obama as compared to a more sweeping ruling.