Bay found that 50.9 per cent of tweets directed at Johnson "was likely politically motivated or not even human" and "a number of these users appear to be Russian trolls".
Only 21.9 per cent of tweets about The Last Jedi were negative in the first place.
According to Mr Bay, there is "evidence of deliberate, organised political influence measures disguised as fan arguments".
"The likely objective of these measures is increasing media coverage of the fandom conflict, thereby adding to and further propagating a narrative of widespread discord and dysfunction in American society," Mr Bay wrote.
"Persuading voters of this narrative remains a strategic goal for the US alt-right movement, as well as the Russian Federation."
Johnson has tweeted in support of the findings, saying they were "consistent with my experience online".
In June, Kelly Marie Train quit Instagram after suffering months of sexist and racist abuse targeting her appearance as Last Jedi character Rose Tico.
Her co-star Daisy Ridley also left social media last year, telling Radio Times it was "highly unhealthy for people's mental health".
