On the other side of the Republican divide, the hawks tend to brush off the public’s reasonable concerns about their policies. Last year, New Jersey’s Republican governor, Chris Christie, delivered a full-barreled attack on libertarianism. To oppose the National Security Agency’s surveillance programs, he suggested, was to place more value on “esoteric” concerns than on the victims of the Sept. 11 attacks.

It may be that Christie and like-minded Republicans could give a compelling answer to Americans who read news stories about surveillance and worry about their privacy or the government’s competence. But to answer them would require first conceding that these widespread concerns are legitimate and shared by people who understand full well that the government has to fight terrorism.

While most voters are ambivalent about foreign policy, the ones who care most about the issue are the ones who have strong views, either hawkish or dovish. And because they’re identifiable constituencies, they tend to have outsize influence on the debate. The many Republican politicians who fall between the dovishness of a Paul and the hawkishness of, say, Senator John McCain generally aren’t the ones who get a lot of media attention.