Learn how the Russians interfered in the 2016 United States presidential election and why authorities think it happened, in these videos excerpted from Putin's Revenge: FRONTLINE. As Donald Trump and Hillary Clinton squared off, Russian president Vladimir Putin took sides. Putin saw links to Russia and potential sympathies in Trump and his political advisers and still held resentment against former Secretary of State Hillary Clinton, whom he believed had meddled in a previous Russian election by ordering anti-Putin protests. Evidence shows that Putin orchestrated efforts to influence the U.S. election, using computer hacking to spread and amplify misinformation (“fake news”) and political polarization in the United States. This resource is part of the FRONTLINE Collection.