It’s not like the Republican party was engaged in a large scale effort to cultivate disinformation from Russian trolls.

The Republican party spent somewhere north of $4B on the 2016 electoral cycle. I believe the Russian troll farm shit was on the order of a couple hundred grand. It just got picked up by national media as a scandal and received tons circulation through free publicity.

And it wasn’t “a few dozen Facebook ads” – it was a pretty large amount of activity

The national news coverage and social media spectacle was orders of magnitude beyond the ad buys themselves. Much like the Trump campaign, the ads got tons of free media - often from the same domestically owned and operated conservative publications - that inflated their presence far beyond what was paid for.

Having a million “ordinary citizens” extol the virtues of some position often just works better as a persuasive argument than having one or two celebrity endorsers

You tend to see one follow the other. So a celebrity will key in on something and kick off a domino effect of "ordinary citizens" talking about it. Conservative media revolves around the cultivation of right-wing celebrities to serve as nexuses for talking points. So a guy like Steven Crowder will sift through the backwash of Forwards From Grandma and pick a few of the stinkiest turds to mainline. Then his horde of followers trend the shit on Twitter in order to make it a national conversation piece.

In this case, the Russian ads were of high enough production quality that they became attractive bait for right-wing media to hash. And so domestic conservative media boosted the foreign propaganda far beyond its initial scope, simple because it resonated with their pro-Trump message.