I watched a fair amount of Donald Trump’s terrorism speech Monday — until he got to this part:

And then I switched off because it’s a ludicrous, boneheaded, badly outdated logic that only works in Seinfeldland. There’s simply no point in taking the rest of the speech seriously except insofar as this is a major party candidate spouting idiocies like this one and there’s still a better-than-one-in-10 chance he could become president.

But it did get me to thinking about how Trump’s campaign marketed the speech before it was delivered: “Donald Trump will declare an end to nation building if elected president, replacing it with what aides described as ‘foreign policy realism’ focused on destroying the Islamic State group and other terrorist organizations.” And this is hardly the first time that Trump’s defenders have characterized his foreign policy approach as realist.

Earlier this year, the hard-working staff here at Spoiler Alerts had some fun at the expense of realists because there were pale echoes of realism in some of Trump’s earlier foreign policy pronouncements. But as someone who teaches international relations, I’m keenly aware of the numerous ways in which Trump’s nostrums deviate from any proper definition of realism. Some realists have been quite outspoken about the ways in which Trump is not a realist. I’ve spoken with several respected international relations scholars who have articulated realist foreign policy proposals that sound similar to ideas Trump has floated. They have been pretty much horrified that Trump is debasing their well-honed arguments.

This campaign has produced a lot of joint letters by foreign policy professionals written in horrified reaction to Trump. There’s this one. And this one. Oh, and this one. Also, this one. Oh, don’t forget this one. But there’s one last one that needs to be cobbled together, and it should come from the self-proclaimed realists in the crowd to distance themselves from Donald Trump.

Realists have banded together to sign letters in the past, but this one would be difficult for them. Eschewing Trump means implicitly or explicitly supporting Hillary Clinton. To realists, Clinton embodies a set of liberal internationalist policies that they believe have damaged U.S. interests considerably.

That said, the essence of realism is that life is nasty, brutish and short, and therefore imperfect choices must often be made. This has certainly been true of many of the signatories of the letters linked to above; many of these signatories are people who, under ordinary circumstances, would back the GOP nominee.

For realists, Hillary Clinton is the flawed but superior choice for president. In the interest of political self-preservation, realists need to get out in front on this. Because the thing about Trump is that every foreign policy position he touches has become less popular over the past calendar year. If realism gets lumped together with Trumpism, that is very, very bad for realists.

Realism is all about how actors survive and thrive in a brutal, anarchic environment. Domestic American politics isn’t quite as brutal as the international system, but it ain’t beanbag either. Realism has important and useful things to say about how to conduct American foreign policy. If the keepers of that paradigm want to be heard after this election cycle, they need to publicly distance themselves from Trump as soon as possible.