It is now well known that Putin funded hundreds of social media trolls in a disinformation campaign that began in 2014. He referred to social media users who were sucked into his disinformation campaign as "useful idiots". It was easy to find the useful idiots because they were everywhere on Facebook and Twitter promoting socially divisive issues. Putin's trolls joined with them in prompting conspiracies and fake news stories that appealed to splinter groups. The goal was to amplify story lines that were socially divisive. The trolls were quick learners. They could write a book about the useful idiots and the issues that divided them from most Americans. They tend to be many of the same issues that Republicans have used to win elections since Richard Nixon's Southern Strategy was implemented. After, Trump won the GOP nomination, with the help of Russian trolls who put the GOP favorite Jeb Bush away early in his campaign, they backed Trump, Bernie Sanders and Jill Stein while doing everything they could to turn Hillary Clinton into Satan. Its hard to determine the number of voters who were influenced by the Russian disinformation campaign but Clinton would have carried Wisconsin, Michigan and Pennsylvania, and won the 2016 election, if she got all of the votes from Democrats who voted for Jill Stein. They also provided Sanders supporters with information that might have discouraged many of them from voting for Clinton in the general election.
Russia and many other nations, including the US, have used disinformation campaigns to serve their interests. However, the social media have changed the disinformation game dramatically. It was expensive and much more difficult to distribute information when a small number of news sources controlled the media. Lyndon Johnson famously announced that he lost the Vietnam war when Walter Cronkite turned against the war. His evening news show, on one of the three major networks, provided millions of Americans with the information that influenced their opinions on major issues. Those days are gone forever. The social media have made the distribution of information more democratic and much less expensive. It wasn't hard for trolls to locate the most likely audience for each of their divisive messages, and the disinformation that they provided did not have to go through an editorial process to determine the veracity of their messages. Everyone has been given an inexpensive megaphone by Facebook and Twitter. The Russian trolls, along with a host of splinter groups have learned how to amplify their freedom speech on the social media which do not employ editors to fact check the information that they broadcast.