The only piece of solid evidence I personally have inventoried so far is about 100k$ ad spend on divisive issues, rather than supporting a particular candidate. That was not massive (compared to campaign billions). It was targeted at regions and individuals. As far as sophistication, some of the ads I have seen didn't have proper grammar and spelling - they didn't seem credible to my bologna detector. These ads were likely a foreign psychological operation, and have no place in our political discourse, but I guess I'd like to see more before we gut the Bill of Rights. If these ads were enough to subvert our democratic institutions, there's nothing but trouble ahead.