It is no longer speculation that Trump is a Russian asset. This article (and a book, American Kompromat, by Craig Unger) put to rest any doubt that the former reality show host was recruited by the KGB to work for Russia:
A former spy for the KGB is making explosive claims about Russia’s efforts to “cultivate” former President Donald Trump as an intelligence asset.
In an interview with the Guardian, former KGB official Yuri Shvets claims that the then-Soviet government starting in the 1980s began to see Trump as a potential instrument for spreading anti-NATO propaganda.
In fact, Shvets says that Soviet agents even planted the idea of running for office in Trump’s head when he visited St. Petersburg and Moscow in 1987.