Ross Douthat concluded his post on the GOP’s missing realists with this suggestion:

By embodying a version of internationalism that clearly put the national interest first, and a form of Daddy-Party toughness that didn’t necessarily entail starting wars willy-nilly, the realists both helped the party manage its internal tensions on foreign policy — bridging divides between isolationists and advocates of “rollback,” paleocons and neocons — and present a credible, competent and non-scary face to the American public as a whole.

That’s something the post-Bush party has thus far failed to do. And if any 2016 candidate wants to unite their party on foreign policy rather than just polarizing it, reaching for the realist legacy might be a decent place to start.

I’m sympathetic to this idea, and I am guessing this was the thinking behind Rand Paul’s decision to identify himself as a realist in his Heritage speech earlier this year. Even so, there are several reasons to doubt the unifying appeal of foreign policy realism in today’s Republican Party. In theory, staking out a realist position in the GOP could be be more unifying than the alternatives because it is potentially less reckless than the foreign policy of hard-liners without being as dovish as non-interventionism. As such, it should offend fewer people and satisfy more than the alternatives, but this seems unlikely to work in practice.

Anyone seen as “reaching for the realist legacy” would run into much greater resistance than he might have fifteen years ago, and he would be perceived as much more of a factional candidate than a consensus-building one. That’s not necessarily a bad thing. George W. Bush was successful at uniting most of the GOP on foreign policy. The results were disastrous because the ideas informing Bush’s policies were awful, and the fact that so many Republicans accepted Bush’s foreign policy early on made it that much harder for them to break with it when it began to fail. As we saw with Romney, a candidate can have a large team of foreign policy advisers including some self-styled realists, and he can still be both deeply polarizing and infuriatingly stupid when he speaks on the subject. Party unity can be overrated and it can have undesirable consequences, so the fact that a realist candidate wouldn’t unite the party on foreign policy isn’t a reason not to run on such a platform.

That said, the obstacles will be considerable. Most Republican hawks deeply loathe Republican realism of the past and present, and the post-Bush years have seen that hostility to realism intensify inside the GOP rather than diminish. The last five years are full of examples of the GOP’s active repudiation of realism and realists on many different occasions, whether it is harping on Obama’s “failure” to support the Green movement, nonsensically attacking New START as a sell-out to Russia, bemoaning policies of diplomatic engagement, or calling for new military interventions. In the wake of all this, it would be contentious and controversial for a Republican politician to identify with the party’s realist tradition. In order for a 2016 candidate to unite the GOP behind a realist platform, he would have to do things that realists have typically not done very well. He would need to draw explicit contrasts with other candidates on these issues, and he would have to go on the offensive rather than wait to be defined by his opponents.