But when liberal cultural politics conflicts with libertarian principles, the liberal views of these voters often prevail: 65 percent think the country should do “whatever it takes” to protect the environment; just 57 percent think the courts should interpret the Constitution strictly, as it was originally written; and 31 percent think it’s more important to control gun ownership than to protect gun rights. These voters nonetheless identify as Republicans because of their views on assistance to the poor and individual responsibility.

Over all, these voters look more like socially moderate Republicans than traditional libertarians. Perhaps the best evidence for this interpretation is that the more Republicans agree with the libertarian view on issues like marijuana or military intervention, the more liberal they get on guns, the environment, the Constitution and gay rights — even when those views conflict with traditional libertarian philosophy. Their seemingly libertarian views might just be a product of the times — they came of age during an era of liberal cultural norms and an unpopular war overseas — not a philosophical commitment to extremely limited government.

The problem for Mr. Paul is that these voters remain a distinct minority in the Republican Party. Two-thirds of Republican leaners disagree with the libertarian view on at least two of the four key issues mentioned above.