Ginsburg has also said that it would be judicial over reach to throw out the whole law, that it should be up to Congress to decide which parts of the bill can be allowed to remain.
Breyer has pointed out that there are lots of parts of the bill that can stand alone, like health benefits for “Indians”. He said that was an “Indian” thing and could remain.
But, I can see that some of the liberal justices might oppose the federal mandate as written, but oppose overturning the whole law.
You could, in theory, see a liberal judge find the individual mandate constitutional but then argue that the bill is not severable.