Let's look further back than these 2015 Moscow real estate shenanigans:
By 2008, Trump's reputation has a businessman had tanked with financial institutions with
only Deutsche Bank willing to invest in his ventures.
Until 2015, Deutsche Bank was involved
in a gigantic scheme using 'mirror trading' to launder money stolen from the Russian state and making it available for spending/re-investment in legitimate western properties... like, say, buying a
dilapidated Miami mansion for an insane mark-up from Donald J. Trump. Choice quote from Trump about this sale in 2016:
What do I have to do with Russia? he replied to reporters questions at a press conference in Doral last summer. You know the closest I came to Russia, I bought a house a number of years ago in Palm Beach
for $40 million, and I sold it to a Russian for $100 million.
We now know he was fresh off the OP's Moscow Trump Tower venture when he said that.
Deutsche Bank AG was fined almost 70 billion USD worldwide for their unethical practices, with the American investigation led by SDNY attorney Preet Bharara (who was unceremoniously fired by Trump shortly before a lenient settlement with the bank.)
Also, from 2008 onward, Russian nationals bought almost 100 million USD worth of Trump real estate in Florida (
'Moscow on the Beach'). All these buyers are conveniently two steps removed from the Putin regime so not touched by sanctions, but we know from the Bill Browder senate testimony that Putin uses 'oligarch trustees' as proxies to re-invest his liquid assets in western holdings.
There is so much smoke around Trump's business empire that it's almost impossible to ignore the possibility that he was a key component of the Russian 'laundromat'. It may be hard for Mueller to prove an actual conspiracy to steal the presidency... but criminal business dealings with a ruthless and sanctioned enemy of the USA should be easier to substantiate.