Since the 2016 United States presidential election, which Russian operatives influenced through a coordinated campaign of disinformation on social media, platforms like Twitter and Facebook have taken steps to address the problem. Thousands of "sock puppet" personas with hundreds of thousands of followers have been taken down on Facebook, for example, and cannot easily be rebuilt. Twitter has reduced the risk that propaganda is spread through automated accounts, or bots.
Such efforts may be helping. The consensus among researchers monitoring the midterm elections this year is that there has been less of the specific sort of interference the Russians engaged in two years ago, when they attempted to aggravate social tensions in the US and foster distrust of our democratic institutions.