A third birthday is often a cause for celebration. But that’s certainly not the case for Obamacare, which was signed into law on March 23 three years ago.

The law has never enjoyed majority support and is likely to become even more unpopular as insurance premiums soar starting next year.

Meanwhile, the fight to stop Obamacare is far from over. It’s simply moved into a new and promising arena: state legislatures.

Florida serves as an example. Last month, Governor Rick Scott (R) agreed to vastly expand Medicaid eligibility to take advantage of a new, federally funded increase in Medicaid payments to the states. As Heritage’s Nina Owcharenko points out, it may seem like a good deal for the state, since Washington will pay a big share of the costs of expansion. “Over time, however, in the majority of states, Medicaid spending will accelerate and dwarf any projected uncompensated care savings.”

That fact isn’t lost on Will Weatherford, the Speaker of Florida’s House. “States are being lured, and I would argue coerced, into expanding programs like Medicaid and passing regulations not through federal mandate but with the promise of free money,” he said at CPAC. “They’re trying to buy us off, one by one.” Weatherford says he has the votes to prevent Medicaid expansion.

It’s a similar story in Arizona, where Governor Jan Brewer (R) has also agreed to the Medicaid expansion but is facing opposition in the state legislature. House Speaker Andy Tobin and Senate President Andy Biggs both agree that Brewer’s plan would be considered a tax increase and would thus require a two-thirds vote in both houses. The outcome there is too close to call.

By pushing back, these state lawmakers are exercising a power that many seemed to have forgotten they had: the ability to impede federal legislation at the state level. Law professor Christian Fritz explains:

Alexander Hamilton identified that role in Federalist No. 26. He described the state legislatures as naturally “jealous guardians of the rights of the citizens” of the state. In the new federal system, the state legislatures, observed Hamilton, could “sound the alarm to the people” when the national government exceeded its rightful powers.

Today’s state legislators have plenty of reasons to become involved. “Most state officials have been elected on platforms that differ greatly from Washington’s policy agenda,” writes Heritage’s Bob Moffit. “Most—though clearly not all—don’t believe the false promise of ‘free’ federal taxpayers’ money.… Courageous and imaginative state officials can not only undertake innovative policy projects on their own, but also resist and repel Washington’s regulatory overreach.”

Thanks to Obamacare, they’re already doing so.