The Office of the Director of National Intelligence releases Jan. 6, 2017 report that Putin,"ordered an influence campaign in 2016 aimed at the U.S. presidential election." In addition, agents from the intelligence office stated they believed that the Russian government prefered Donald Trump over Hillary Clinton, and pursued action to undermine Americans faith in the election.
Russian hackers obtained confidential files from the DNC and subsequently leaked those documents on WikiLeaks.
Trump took a hands off approach to the topic, and avoided naming Russia as the perpetrator. Instead, he lead the American people to believe it could be anyone, maybe China.
According to Christopher Steele, a respected former British Intelligence officer, Russia has been blackmailing Trump for at least the last five years, and have been regularly feeding him information.
Paul Manafort, former trump campaign chair, often contacted russian officials. Sergei Ryabkov, Russian Deputy Foreign Minister, confirmed these contacts to a Russian media outlet in November 2016. Trump denies all claims.
Flynn often attended Russian state media Gala's with Putin. He was in contact with Russia before Trump took office illegally negotiating the relaxation of the sanctions placed on Russia by the Obama administration in response to the DNC hacking. Flynn ulitmately resigned from the administration but Trump did not condone his actions. Instead, he stated that Flynn was a wonderful man, who had done nothing wrong, and had been wrongly persecuted by the media.
Trump associates met with Russian diplomats in New York to work on a plan rubber stamped by Putin. Flynn would have inacted this plan. Although Flynn is out, the plan could still be in play, as the White House blew off the report blaming the 'Fake' media.
Without seeing Presidents Trumps tax returns it is hard to estimate how much financial leverage Russia has on Trump. It can be infered to be influential, however, as Trumps Miss Universe pageant was held in Moscow in 2013 for $20 million. Also, it is suspicious when Trump Jr. says,"Russians make up a pretty diproportionate cross-section of a lot of our assets."