On the surface, the Christie-King-establishment vs. Paul-Cruz-libertarian donnybrook that has broken out over the last few days is about national security — specifically, the NSA snooping programs. In truth, national security is but the trigger to a much broader discussion that needs to happen. The fault lines that have developed over the last decade in the GOP have divided the party on spending, taxes, the size and role of government, immigration, gay rights, and America’s place in a changing world.

In short, the Republican Party is in the process of reinventing itself. And the debate now underway between the two dominant strains of conservative thought will not only determine the future of the Republican Party, but also have a great impact on who will be the GOP standard bearer in 2016.

Perhaps the biggest story in Republican politics in 2013 has been the rise of the libertarian right in the Senate and the man who has shown genuine leadership ability in facilitating that rise. Rand Paul has stepped into a leadership void created by the ineffectiveness of Minority Leader Mitch McConnell and altered the tone and tenor of Senate debates. The power axis of Paul, Mike Lee of Utah, and Ted Cruz of Texas has given Senate Republicans something they haven’t had in years: voices that speak with a passion and coherence about principles while pushing a recognizable, consistent agenda.

It should come as no surprise that traditional, establishment conservatives would find a way to fight back. But Chris Christie as the messenger? The Northeast Republican has the credentials, but would hardly be the first choice of most establishmentarians. Despite still being mentioned as a possible candidate in 2016, many rank-and-file Republicans have virtually abandoned Christie, given his embrace of President Obama just days before the 2012 election and his apostate views on gun control and immigration reform.

But Christie may not feel he’s dead yet. Speaking at the Aspen Institute on a panel with other GOP governors, the New Jersey governor came down hard on Senator Paul and other libertarians for their opposition to the NSA surveillance programs.

As a former prosecutor who was appointed by President George W. Bush on Sept. 10, 2001, I just want us to be really cautious, because this strain of libertarianism that’s going through both parties right now and making big headlines, I think, is a very dangerous thought.

Did he mean Rand Paul specifically?

You can name any number of people and he’s one of them. These esoteric, intellectual debates — I want them to come to New Jersey and sit across from the widows and the orphans and have that conversation. And they won’t, because that’s a much tougher conversation to have.

Accusing the libertarians of being soft on terrorism exposes Paul’s main vulnerability. Indeed, the whole non-interventionist strain that runs through the libertarian right goes far beyond defending civil liberties and envisions a world with a greatly reduced role for America, a reduced military — indeed a revolutionary change in the national-security state.

Christie’s attack was followed by a similar assault from Representative Peter King, chairman of the House Homeland Security Committee and a politician desperately looking for an issue to ride to the Republican nomination in 2016.

The New Yorker didn’t pull any punches:

“To me the overriding concern here has to be national defense, national security, and not be apologizing for America,” King said. “When you have Rand Paul actually comparing [Edward] Snowden to Martin Luther King, Jr., or Henry David Thoreau, this is madness. This is the anti-war left wing Democrats of the 1960s that nominated George McGovern and destroyed their party for almost twenty years. I don’t want that happening to our party.”

To accuse Paul of virtually “blaming America first” (and to mention George McGovern in the same breath) is to throw down the gauntlet to the libertarians on issues that have defined the Republican Party for more than 40 years — unflinching support for national defense and a strong, aggressive foreign policy that puts America first.

For the knockout blow, King used the “I” word to describe Paul and the libertarian tribe:

“I thought it was absolutely disgraceful that so many Republicans voted to defund the NSA program, which has done so much to protect our country,” King said. “This is an isolationist streak that is in our party. It goes totally against the party of Eisenhower, Reagan, Bush. We are party of national defense, we’re a party who did so much to protect the country over the last few years.”

What the NSA program has to do with isolationism, King doesn’t say. But if there is anything that is going to keep the libertarians from rising to dominance in the Republican Party, it is the sense that they wish to take the GOP back to the days of Robert Taft and his brand of non-interventionist foreign policy. Taft opposed aid to the allies prior to our entrance into World War II. After the war, he opposed the U.S. joining alliances such as NATO, opposed U.S. participation in the UN, and generally felt that Fortress America, protected by the two great oceans, could afford us the security we needed.