What's With the Neoliberal Hysteria Over Russia?

Centrists, liberals, neocons, etc have gotten in the habit of accusing populists, nationalists, leftists, etc of being, at least, stooges of Russia and, sometimes, active agents of them. The core idea behind this accusation is that there was a Western consensus and order that Russia wants to see crumble. So they undermine this order in nefarious plots to get candidates who oppose this order elected. Or something.

The most high profile manifestation of this theory was the Trump-Russia debacle which, predictably, turned up totally empty. But accusations about Russian "ties" has been lobbed at anti establishment movements throughout the west, both left and right. So, what's the purpose of all this? We now pretty much know that the Russian efforts were, at most, some extremely paltry low budget internet ads and memes and, possibly, some Russian hacker lucked out with the DNC emails. But why has the establishment across the west latched onto this as some grand conspiracy?

Offhand, my guess is that they know, on some deep level, that "the establishmentarians versus the populist outsiders" is a losing game for them. So, instead of changing policy course so the people won't dislike them so much, they are essentially trying to bring the terms of debate to "the establishment versus Russia". Then, people might not like the establishment but they certainly prefer them to Russia.

It's a lot easier to quash out populist insurgents if you dismiss them as Russian stooges. So that's exactly what they do.