McConnell, a master of byzantine Senate procedure, immediately realized that, as a tax, the individual mandate would be subject to the budget reconciliation process, which exempted it from the filibuster. In other words, McConnell had just struck upon how to repeal Obamacare with a simple majority vote.

The Kentucky Republican called a handful of top aides into his office and told them, "Figure out how to repeal this through reconciliation. I want to do this." McConnell ordered a repeal plan ready in the event the GOP took back control of the Senate in November -- ironic considering Democrats used the same process more than two years earlier in a successful, last-shot effort to muscle the reforms into law.

In the months that followed, top GOP Senate aides held regular strategy meetings to plot a path forward. Using the reconciliation process would be complicated and contentious. Senate rules would require Republicans to demonstrate to the parliamentarian that their repeal provisions would affect spending or revenue and Democrats were sure to challenge them every step of the way. So the meetings were small and secret.

"You're going in to make an argument. You don't want to preview your entire argument to the other side ahead of time," said a McConnell aide who participated in the planning. "There was concern that all of this would leak out."

By Election Day, Senate Republicans were ready to, as McConnell put it, "take this monstrosity down."

"We were prepared to do that had we had the votes to do it after the election. Well, the election didn't turn out the way we wanted it to," McConnell told National Journal in an interview. "The monstrosity has ... begun to be implemented and we're not giving up the fight."

Indeed, when it comes to legislative strategy, McConnell plays long ball. Beginning in 2009, the Republican leader led the push to unify his colleagues against Democrats' health care plans, an effort that almost derailed Obamacare. In 2010, Republicans, helped in part by public opposition to the law, won back the House and picked up seats in the Senate. Last year, GOP presidential nominee Mitt Romney's embrace of the individual mandate while Massachusetts governor largely neutralized what had been a potent political issue.

But, in the next two years, Republicans are looking to bring the issue back in a big way. And they'll start by trying to brand the law as one that costs too much and is not working as promised.

Democrats will be tempted to continue to write off the incoming fire as the empty rhetoric of a party fighting old battles. But that would be a mistake. During the health care debate, the GOP's coordinated attacks helped turn public opinion against reform. And in the past two years, no more than 45 percent of the public has viewed Obamacare favorably, according to the Kaiser Family Foundation's tracking polls. Perhaps even more dangerous for Democrats, now-debunked myths spread by Republicans and conservative media remain lodged in the public consciousness. For instance, 40 percent of the public still believes the law includes "death panels."