Missouri voters dealt Obamacare a significant setback yesterday, approving a statewide ballot measure by an overwhelming 71 percent.

The vote was the first time citizens had an opportunity to cast a ballot on the unpopular healthcare law. Missouri's measure prohibits the federal government from enforcing the individual mandate to buy health insurance. The victory sends a strong message about Obamacare in a bellwether state.

"We're excited and proud to be ground zero in the battle against this misbegotten federal healthcare reform," said Missouri Lt. Gov. Peter Kinder in an exclusive interview. "We had the first vote in the nation in the Show-Me State. And we're showing the nation the way to repeal and replace this big government, big bureaucracy, one-size-fits-all law."

The vote in favor of Proposition C came despite a well-funded campaign from the Missouri Hospital Association to oppose the ballot measure. Contrary to a myth spread by the left, opponents had a sizable advantage in resources. The Missouri Hospital Association spent more than $400,000, while Missourians for Health Care Freedom estimated its spending would total about $100,000 in support of Proposition C.

The vote came just one day after a federal judge allowed Virginia's case against the individual mandate to proceed. Virginia Atty. Gen. Ken Cuccinelli challenged the Obamacare provision on the grounds that the federal government cannot regulate a person's decision to purchase a product such as insurance. U.S. District Judge Henry E. Hudson rejected the Obama Administration's request to dismiss the case Monday.

This week's events are symbolic in the effort to repeal Obamacare. Missouri is one of four states to put Obamacare on the ballot this year. The other three—Arizona, Florida and Oklahoma—have constitutional amendments up for consideration in November.

The statewide efforts stem from the American Legislative Exchange Council's Freedom of Choice in Health Care Act. The model legislation protects a patient's rights to pay directly for medical services and prohibits the federal government from imposing penalties on individuals for declining participation in a healthcare plan. Five states have already enacted statutory measures: Arizona, Georgia, Idaho, Louisiana and Virginia. Lawmakers in 38 states have introduced the model legislation and three other states are planning to do so soon.

The American Legislative Exchange Council holds its annual meeting later this week in San Diego. Kinder will be on hand to discuss Missouri's efforts to halt Obamacare. Reps. Rob Bishop (R.-Utah) and John Shadegg (R.-Ariz.) will join him for a session on federalism. Another group of health care experts will debate repeal vs. implementation of the health care law.

In addition to the Missouri ballot measure, the Republican Kinder is also challenging Obamacare in court with three other plaintiffs. He said passage of the ballot measure will bolster his lawsuit.

"My case will be strengthened," he said. "It will strengthen the multi-state effort to roll back this federal law."

One of the plaintiffs in the Kinder lawsuit is Dale Lee Morris, a 74-year-old enrolled in Medicare Advantage. She argues changes to Medicare Advantage will reduce her access to healthcare. Obamacare mandates deeps cuts to Medicare Advantage, prompting a sharp reduction in enrollment in the coming years.

Kinder's lawsuit differs from other states because he's pursuing the case without the support of the state's Democratic governor or Democratic attorney general. He said that hasn't dissuaded him.

"Fortune favors the bold," Kinder said. "We need to be leading out front on this. We need other states to put it on the ballot like we did. Or pass it through their state legislatures. And continue the grassroots uprising that's spreading like a prairie fire all across America."

Mr. Bluey, a contributing editor to Human Events, is director of the Center for Media & Public Policy at The Heritage Foundation.