Who lost the libertarians?†It’s a question you hear a lot from conservatives of late. The reason should be obvious to anyone who has followed the conservative movement’s internecine intellectual frictions over the last decade — or decades. Self-described libertarians are a minority, even among the ranks of people one could properly describe as libertarian. On many, or even most, contentious public-policy issues — economics, gun rights, health care, free speech, regulation, constitutional interpretation — most support for the libertarian position actually comes from people who describe themselves as conservatives. In other words, conservatives tend to be libertarian, but libertarians...