More likely the entire Trump family is financially in debt to Russian bankers/lenders. Of course, this could be leverage to turn him into an "agent". Or possibly the Secret Dossier that hinted at incriminating photos of Trump held by the Russians is true.
For some time I've been absolutely convinced that a financial link exists and that the Russians also have video. When ever Vlad wants something done to help Russia (like undermining NATO) he just needs to remind the President that he has the evidence in his safe. I am also convinced that, once he's out of office, Trump will be going to jail.....and he may be joined by some of those close to him.
