In the end, as Marcy has been explaining for what must be years now, the conspiracy was pretty simple and obvious:
The Trumps were monetizing this running-for-President thing, and they were happy to make campaign promises to Russians bearing dirt, because the point wasn’t to actually win the election. It was about the hundreds of millions they stood to gain….
The Russians exploited Trump’s most venal instincts and those of all the people around him. And all the election help and policy payoffs were just side shows to Trump. So long as he showed a willingness to damage Hillary Clinton in any way available, the Russians were happy to have him believe this was just about a silly tower in Moscow.
Source: The Quid Pro Quo Was Even Tighter Than I Imagined – emptywheel