What Paul seems to understand is that the Republican base doesn’t really have a detailed set of foreign policy positions: What it has, instead, is the cluster of sympathies and instincts (pro-Israel, pro-military, nationalist rather than globalist, fretful about radical Islam, skeptical of international institutions) that Walter Russell Mead has famously dubbed “Jacksonianism,” which can incline G.O.P. voters for or against different policy choices depending on how those options are presented. So if you want to reach the base, and move the party, you need to speak the base’s language and respect its basic outlook on the world — which is something that Paul has done much more successfully than many members of Washington-based realist community.

This means, for instance, talking about war powers rather than the U.N. when the White House is contemplating a war of choice. It means invoking the constitution rather than international law to critique Obama’s drone campaign. It means invoking Israel’s own internal debates, rather than just blasting AIPAC’s influence in Washington, to make the case for caution vis-a-vis a military strike on Iran. And it means finding ways to be a party loyalist on some votes in order to gain maneuvering room on others — as Paul tried to do, admittedly somewhat clumsily, by voting against cloture for Hagel but then voting to approve nomination.