It appears that Trump was living off dirty Russian mob/oligarch money for years before he ran for the GOP nomination, which is how he stayed afloat despite not being able to get loans from any legitimate bank. wnycstudios.org/podcasts/trump…
Back in March 2017, just based on the reporting that had come out at that point, it already seemed clear that this was the nature of the Trump/Russia stuff. It wasn't spy-thriller treason, it was just run-of-the-mill kleptocratic corruption.
This is the most obvious, Occam's Razor, explanation for why Trump is fighting so hard to keep his tax returns out of the public eye. It also explains why he's so hell bent on undermining Fusion GPS. Because they had the goods in terms of what a corrupt businessman he was.
Given that Fusion was at first hired by (and thus reported to) establishment Republicans, this tweet from Lindsey Graham perhaps makes more sense. May 2016 was right around the time Fusion stopped working for folks in the GOP. 
Much of the shadiness that has come out via reporting like this had already been uncovered by the Fusion GPS researchers and had been shared with the Republican Party. The GOP knew full well they were about to cast their lot with a deeply corrupt person. wnycstudios.org/podcasts/trump…
I suspect that this is why Lindsey thought Trump would destroy the GOP (and the GOP would deserve it). Because Graham knew that covering for Trump's corruption would sully the reputation of the GOP for decades.
Between this corruption and the emerging Parnas/Fruman/Giuliani story regarding campaign finance violations, ever more people in the GOP are at risk of exposure (in moral if not legal terms). And so, like Trump, their only play is to go on the offensive, to accuse the accusers.
What a sad, sordid, and cowardly chapter for the party of Lincoln. Hard for me to understand how any person of integrity could continue to be affiliated with this toxic family and the party they've successfully taken over lock, stock, and barrel.
If you haven't been following the work of the incredible journalists at Trump, Inc...here's the home page with links to the scores of stories they've done documenting the historical and ongoing corruption of our current President's family. wnycstudios.org/podcasts/trump…
For crying out loud, this story about Trump likely engaging in money laundering for the Iranian freaking Revolutionary Guard came out in March 2017 and it had zero effect on GOP opinion of the guy. newyorker.com/magazine/2017/…
