As everyone knows by now in the aftermath of the "loud" debate over ObamaCare, the feds will be working to implement this massive (expensive) new program over the next several years, but it will take time. 

Of course, many people and politicians are looking for ways to stop and/or overturn the program via legal and political means.  "Legal", in the sense of the budding lawsuits that are being filed to challege various aspects of the program, not the least of which is the fact that it forces individual Americans to buy a commercial product for the first time in American history.  And "political" in the sense of introducing legislation to re-write and/or repeal the bill entirely - which of course will rely on having majorities in Congress that are so inclined, which will have to wait until after the coming November elections.

But this overlooks the individual state governments, which do have some options themselves that could be used to resist ObamaCare, not the least of which because they are called on to play such a large role in the program.

Over the course of the past year as the Obama administration and Congress have been busy proposing and debating the creation of new, bigger government programs, the public resistance to bigger and more expensive government has increased, which also translated into more state legislators introducing legislation to have their states opt out of such programs (like ObamaCare).

A recent Rasmussen poll would seem to confirm the resurgence of public support for federalism.  The survey found that 59% of voters agree that states should be able to opt out of federal programs that they oppose.  (Only 25% disagreed, and 15% didn't know)

Sixty-three percent (63%) of voters also think
states should have the right to opt out of federally mandated programs
if the federal government doesn’t help pay for them. Seventeen percent
(17%) say states should not have the right to opt out of federally
mandated programs. ...

Seventy-six percent (76%) of Republicans and 67% of
voters not affiliated with either major party say states should have
the right to opt out of federal programs with which they don’t agree.
Just 37% of Democrats agree.

The folks in Montana - Democrat Governor included - have struck a blow for states' rights and against the "enlarged" understanding of the Interstate Commerce Clause of the Constitution (through which so much of big government has been driven).

From Volokh: